The Roman Catholic Church is the only true one among so many other churches. Almighty God has carefully guarded her, and brought her victoriously through all the persecutions of her enemies. Hence, as St. Iraeneus says (Lib. 3, cap. 3, n. 2), all should depend on the Roman Church as on their fountain and head. This is the Church founded by Jesus Christ, and propagated by the Apostles; and although in the commencement persecuted and contradicted by all, as the Jews said to St. Paul in Rome: "For as concerning this sect (thus they called the Church), we know that it is gainsayed every where" (Acts, xxviii, 22); still she always remained firm and constant despite the vicious attacks of her enemies. St. Augustine says that heresies are only embraced by those who had they persevered in the faith, would be lost by the irregularity of their lives (St. Aug. de Va. Rel. c. 8.).

Great as the persecutions were which the Church suffered from idolatry, still greater were those she had to endure from the heretics which sprang from her own bosom, by means of wicked men, who, either through pride or ambition, or the desire of sensual license, endeavoured to rend the bowels of their parent.

Heresy has been called a canker: "It spreadeth like a cancer" (II. Tim. ii, 17); for as a cancer infects the whole body, so heresy infects the whole soul, the mind, the heart, the intellect, and the will. It is also called a plague, for it not only infects the person contaminated with it, but those who associate with him, and the fact is, that the spread of this plague in the world has injured the Church more than idolatry, and this good mother has suffered more from her own children than from her enemies.

A Heretic is one who "chooses". His Choice is his own "opinion" as opposed to the constant teaching of the Church which which Christ has given us as the infallible guide of Salvation.

St. Augustine wisely considers a heretic to be worse than a Murderer because a person who kills the body ultimately can have no power to harm the soul but a heretic unlike the former draws his victim to eternal perdition.

What is Heresy?

"Heresy consists in a stubborn denial of truths which have been defined an proposed by the Church as divinely revealed doctrines." (Canon 1324-1325 of the 1917 Code of Canon Law).

What must we believe?

"By the divine and Catholic Faith, all those things must be believed which are contained in the written Word of God and in tradition, and those which are proposed by the Church, either in a solemn pronouncement or in her ordinaryand universal magisterium,to be believed as divinely revealed." (Vatican Council I, Denzinger 1792)

We can also quote St Vincent of Lerins (from his Commonitory written circa 434) in his admonition to the Faithful of how to find the true Faith. In the aftermath of the suppression of the Arian heresy in the fourth century St Vincent encountered some difficulties in ensuring people knew and practised the true Faith because of the doctrinal confusion that still followed from that heresy. He, therefore, asked himself and others: "How and by what sure and, so to speak, universal rule shall I be able to distinguish the truth of the Catholic Faith from the falsehood of heretical depravity?" The answer, adduced both from himself and from other very learned and holy men of the time, was everywhere the same: "We must, the Lord helping, fortify our belief in two ways: By the authority of the Divine Law. By the Tradition of the Catholic Church. Moreover, in the Catholic Church itself, all possible care must be taken, that we hold that faith which has been believed everywhere, always, by all, from the beginning." He further asked: "What if some novel contagion seeks to infect not merely an insignificant portion of the Church, but the whole Church?" The answer was: "It will be his (i.e. the individual's) case to cleave to antiquity, which at this day cannot possibly be seduced by any brand of novelty."

Who does not believe all those things taught by the Magisterium of the Church?

"Any baptized person who … obstinately denies or doubts any of the truths proposed for belief by divine and Catholic faith, is a heretic." (C. 1325)

He who dissents even in one point from divinely revealed truth absolutely rejects all faith, since he thereby refuses to honour God as the supreme truth and the formal motive of faith. "In many things they are with me, in a few things not with me; but in those few things in which they are not with me the many things in which they are will not profit them" (St Augustine in Psalm. LIV, n.19). And this indeed most deservedly; for they who take from Christian doctrine what they please lean on their own judgements, not on faith; and not bringing into captivity every understanding unto the obedience of Christ (Cor. X,5), they more truly obey themselves than God. "You, who believe what you like of the gospels and believe not what you like, believe yourselves rather than the gospel" ' (St Augustine, lib. XVII., Contra Faustum Manichaeum, cap. 3).

What are the Effects of Heresy?

Heresy deprives one of being a Member of the Church and places them in the state of perdition unless they abjure their error and return to the Catholic Faith (The Council of Florence, Dz 714). Heresy also deprives the offender of access to any of the Churches sacraments unless he first repents of his crime (Canons 731, 765, 795,985,1240).

St. Augustine expressly states that "whoever draws away anyone from the universal Church to any sect, is a murderer and a Child of Satan" - Ad Petilian, 2, 13.

How many truths does a person have to deny to become a Heretic?

It suffices to deny one divinely revealed truth of the Catholic Faith to become a heretic and place oneself outside the Church (St. Thomas Aquinas, Summa Theologica II, II, Q 5, Art. 3.). As St. Jerome put it "If you wander off the track a bit, it makes no difference if you veer to the right or to the left, the important thing is that you are not on the right road." - Commentary on St. Matthew

What are we to think of Catholics who support Heretics?

Those who support heretics come under the condemnation of the IV Lateran Council which declared that "Those who give credence to the teachings of heretics, as well as those who receive, defend, or patronize them, are excommunicated.”

Further he who to support heresy distorts the Sacred Scriptures from their genuine and true meaning is guilty of the greatest injury to the Word of God; and against this crime we are warned by the Prince of the Apostles: "There are certain things hard to be understood, which the unlearned and unstable wrest, as they also do other Scriptures, to their own destruction" (II Peter 3:16 Cf also Council of Trent, Decree on Edition and Use of the Sacred Books," Session IV, DNZ:786

The 1917 Code of Canon Law affirms that Catholics have a duty to reject error and heresy and all that works against the faith in the following words: Canon 1325.1 - “The faithful are bound to profess their faith openly whenever under the circumstances silence, evasion, or their manner of acting would otherwise implicitly amount to a denial of the faith, or would involve contempt of religion, an offense to God, or scandal to the neighbor.”

St. Francis de Sales on this point tells us that "It is our duty to denounce as strongly as we can heretical and schismatic sects and their leaders. It is an act of charity to cry out against the wolf when he is among the sheep, wherever he is." -  Introduction to the Devout Life, III, 29.

Why does God permit Heresy?

St. Paul says: "There must be heresies, that they also who are reproved may be made manifest among you" (I. Cor. ii, 19). St. Augustine, explaining this text, says that as fire is necessary to purify silver, and separate it from the dross, so heresies are necessary to prove the good Christians among the bad, and to separate the true from the false doctrine. The pride of the heretics makes them presume that they know the true faith, and that the Catholic Church is in error, but here is the mistake: our reason is not sufficient to tell us the true faith, since the truths of Divine Faith are above reason; we should, therefore, hold by that faith which God has revealed to his Church, and which the Church teaches, which is, as the Apostle says, "the pillar and the ground of truth" (I. Tim. 3:15). Hence, as St. Iraeneus says, "It is necessary that all should depend on the Roman Church as their head and fountain; all Churches should agree with this Church on account of her priority of principality, for there the traditions delivered by the Apostles have always been preserved" (St. Iraen. lib, 3, c. 3); and by the tradition derived from the Apostles which the Church founded at Rome preserves, and the Faith preserved by the succession of the Bishops, we confound those who through blindness or an evil conscience draw false conclusions (Ibid).

"Do you wish to know," says St. Augustine, "which is the true Church of Christ? Count those priests who, in a regular succession have succeeded St. Peter., who is the Rock, against which the gates of hell will not prevail" (St. Aug. in Ps. contra part Donat.): and the holy Doctor alleges as one of the reasons which detain him in the Catholic Church, the succession of Bishops to the present time in the See of St. Peter" (Epis. fund, c. 4, n. 5); for in truth the uninterrupted succession from the Apostles and disciples is characteristic of the Catholic Church and of no other.

It was the will of the Almighty that the Church in which the true faith was preserved should be one, that all the faithful might profess the one faith, but the devil, St. Cyprian says (de Unitate Ecclesie), invented heresies to destroy faith, and divide unity. The enemy has caused mankind to establish many different churches, so that each, following the faith of his own particular one, in opposition to that of others, the true faith might be confused, and as many false faiths formed as there are different churches, or rather different individuals. This is especially the case in England, where we see as many religions as families, and even families themselves divided in faith, each individual following his own. St. Cyprian, then, justly says that God has disposed that the true faith should be preserved in the Roman Church alone, so that there being but one Church there should be but one faith and one doctrine for all the faithful. St. Optatus Milevitanus, writing to Parmenianus, says, also: "You cannot be ignorant that the Episcopal Chair of St. Peter was first placed in the city of Rome, in which one chair unity is observed by all" (St. Opt. l. 2, cont. Parmen.)

Do Heretics Have Unity?

The heretics, too, boast of the unity of their Churches, but St. Augustine says that it is unity against unity. "What unity," says the Saint, "can all those churches have which are divided from the Catholic Church, which is the only true one; they are but as so many useless branches cut off from the Vine, the Catholic Church, which is always firmly rooted. This is the One, Holy, True, and Catholic Church, opposing all heresies; it may be opposed, but cannot be conquered. All heresies come forth from it, like useless shoots cut off from the vine, but it still remains firmly rooted in charity, and the gates of hell shall not prevail against it." (St. Aug. lib. 1, de Symbol ad Cath. c. 6).

St. Jerome says that the very fact of the heretics forming a Church apart from the Roman Church, is a proof, of itself, that they are followers of error, and disciples of the devil, described by the Apostle, as "giving heed to spirits of error and doctrines of devils" (I. Tim iv. 1). The Lutherans and Calvinists say, just as the Donatists did before them, that the Catholic Church preserved the true faith down to a certain period - some say to the third, some to the fourth, some to the fifth century - but that after that the true doctrine was corrupted, and the spouse of Christ became an adulteress. This supposition, however, refutes itself; for, granting that them Roman Catholic Church was the Church first founded by Christ, it could never fail, for our Lord himself promised that the gates of hell never should prevail against it: "I say unto you that you are Peter, and on this Rock I will build my church, and the gates of hell shall not prevail against it" (Matt. 16:18). It being certain, then, that the Roman Catholic Church was the true one, as Gerard, one of the first ministers of Luther, admits (Gerard de Eccles. cap. 11, sec. 6) it to have been for the first five hundred years, and to have preserved the Apostolic doctrine during that period, it follows that it must always have remained so, for the spouse of Christ as St. Cyprian says, could never become an adulteress.

Contrary to what might be asserted by the false notion of ecumenism as some have sought to promote, the Church does not seek her unity from those outside the Church. She already has unity! For this reason we say in the creed "I believe in One, Holy, Catholic and Apostolic Church". The Church is one in her faith, government and sacraments. She has no need of those outside the Church. Its they who need to come to the ark of Salvation. This household (The Church), the Holy Spirit designates and points out in the Psalms, saying, "God, who maketh men to dwell with one mind in a house" (Ps. LXVIII, 6). In the house of God, in the church of Christ, men dwell with one mind and continue in concord and simplicity. When a person leaves the Church by heresy he is to be regarded as a "heathen and a publican" according to Christ (Matt 18:17). He is not be regarded as having any unity in an of himself, but as having departed from the household of faith, that foundation and Pillar of truth (1Tim 3:15).

Can Heresy destroy the Church?

No! The Church is by her very nature indefectible. Her adversaries cannot overcome her. We have the assurance of Christ that the Church will never be totally destroyed as he clearly states that "the gates of Hell will no prevail against it" (Matt 16:18). Yet this promise of indefectibility is not given to any person (this includes the Pope), state or country but only the Church as whole. For this reason did St. Athanasius say that even if the Church were reduced to handful of people, if they hold to tradition, they would be the true Church, since holding to the deposit of faith and rejecting it is what makes the difference between being a Catholic and being a Heretic.

St. Cyprian states that "who, then, is so wicked and faithless, who is so insane with the madness of discord, that either he should believe that the unity of God can be divided, or should dare to rend it - the garment of the Lord - the church of Christ? He Himself in His Gospel warns us, and teaches, saying, "And there shall be one flock and one shepherd" (John X, 16). And does any one believe that in one place there can be either many shepherds or many flocks? The Apostle Paul, moreover, urging upon us this same unity, beseeches and exhorts, saying, "I beseech you, brethren, by the name of our Lord Jesus Christ, that ye all speak the same thing, and that there be no schisms among you; but that ye be joined together in the same mind and in the same judgement" (1 Cor. I,10). And again he says: "Forbearing one another in love, endeavouring to keep the unity of the Spirit in the bond of peace" (Eph. IV, 8). Do you think that you can stand and live if you withdraw from the church, building for yourself other homes and a different dwelling, when it is said to Rahab, in whom was prefigured the church: "Thy father, and thy mother, and thy brethren, and all the house of thy father, thou shalt gather unto thee into thine house; and it shall come to pass, whosoever shall go abroad beyond the door of thine house, his blood shall be upon his own head?" (Josh. II, 19). Also, the sacrament of the Passover contains nothing else in the law of the Exodus than that the lamb which is slain in the figure of Christ should be eaten in one house. God speaks, saying: "In one house shall ye eat it; ye shall not send its flesh abroad from the house." (Ex. XII, 46). The flesh of Christ, and the holy of the Lord, cannot be sent abroad, nor is there any other home to believers but the one church. This home, this household (hospitium) of unanimity, the Holy Spirit designates and points out in the Psalms, saying, "God, who maketh men to dwell with one mind in a house" (Ps. LXVIII, 6). In the house of God, in the church of Christ, men dwell with one mind and continue in concord and simplicity.'

The Fathers of the Church have always regarded the indefectibility of the Church as being as true as the very existence of the Church itself.

Some quotes from the Fathers are as follows:

St. Ignatius of Antioch

"The Lord Permitted myrrh to be poured on his head that He might breathe incorruption upon the Church" - Ephesians 17.1.

St. Irenaeus

The Church is Immutable and always remains the same - Adversus Haer. III, 24, I.

St. Athanasius

"The Church will go on enlightening the world with its brilliance and existing forever, just like the Sun and the Moon" - In Psalm 88:38

St. Ambrose

"The Church is like the moon, it may wane at times but never be destroy, it may be darkened but it can never disappear."

St. Jerome

"We understand accordingly that the Church can be stricken with persecutions right up to the end of the world but can never be overcome. And this will be, because the lord God almighty, its God, promised that He would see to it, and His promise is the very law of nature" - In Amos

What is the Mind of the Church On Heresy and Heretics?

We cannot think of a Saint, Church Father, Doctor or Catholic theologian who has not fought with great zeal or rigor against heresy and Heretics. St. Anthony of Padua for example who is well know for the numerous miracles he worked and his great humility and meekness has always received from the Church the title of "The Hammer of Heretics" for he was exemplary in his dealing with heretics with a firmness combined with meekness and unsurpassed heavenly wisdom which brought about the conversion of numerous heretics. In fact after his death and canonization it was found that till this very day his tongue has remain uncorrupted. We should not be surprised at this for it was by this tongue that he professed the truth of the Faith to the edification of the Church and the destruction of the Kingdom of Satin, which is founded on Heresy and perversity.

Heretics, who, instead of learning from the Church the dogmas they should believe, wish to teach her false and perverse dogmas of their own and say that they have the Scriptures on their side, which are the fountain of truth, and that it is not by reading, but by understanding, them, that the truth can be found. Heretics of every sort avail themselves of the Scriptures to prove their errors, but we should not interpret the Scripture according to our own private opinions, which frequently lead us astray, but according to the teaching of the Holy Church which is appointed the Mistress of true doctrine, and to whom God has manifested the true sense of the Scriptures books. This is the Church, as the Apostle tells us, which has been appointed the pillar and the ground of truth: "that thou mayest know how thou oughtest to behave thyself in the house of God, which is the Church of the living God, the pillar and the ground of truth" (I. Tim. iii, 15.) Hence St. Leo says that the Catholic faith despises the errors of heretics barking against the Church, who deceived by the vanity of worldly wisdom, have departed from the truth of the Gospel - (St. Leo, Ser. 8, de Nat Dim.)

Below we have listed the some of the Teachings of the Church on this issue for the benefit of the reader:

St. Paul "A man after the first and second admonish avoid: knowing that he that is such a one is subverted and sins, being condemned by his own judgment." St. Titus 3:10-11

St. John "Anyone who does not abide in the doctrine of Christ, has not God." 2 Jn 1:9

I Lateran Council - If anyone does not profess properly and truthfully all that has been handed down and taught publicly to the Holy, Catholic, and Apostolic Church of God, to the last detail in word and intention: let him be anathema. (HISTORY OF THE COUNCILS, Bishop Karl Joseph von Hefele, Edinburgh: Clark Company, 1872-1876)

VII Council of Carthage - Heretics are Antichrists and adversaries of Christ. (PL 4:1051)

IV Lateran Council - We excommunicate and anathematize every heresy, condemning all heretics under whatever names they may be known; for, while they have different faces, they are nevertheless bound to each other by their tails. Secular authorities shall be compelled to exterminate all heretics to the best of their ability, and if, from sufficient evidence, it is apparent that a bishop is negligent in cleansing his diocese of heretical wickedness, let him be deposed and another substituted who will confound heretical depravity. But if any of them by damnable obstinacy disapprove, from this very fact let them be regarded as heretics.

Pope St. Martin I - If anyone does not with mind and lips reject and anathematize all abominable heretics together with their impious writings, even to the single least portion, let such a person be condemned. (Canon 18, Lateran Council, DNZ: 271-272)

St. Cyprian - Whoever withdraws and departs from the Church will be guilty, even though he has attained grace in the Church. That he will perish will be imputed to himself. (Epistle 69:4).

St. Cyprian: "He who has not the Church for his Mother cannot have God as his Father." (Patrologiae Cursus Completus: Series Graca, Fr. J. P. Migne, Paris: 1866, 4:502)

St. Cyprian: "He is no Christian who is not in Christ's Church." (Epistle to Antonianus," 52)

St. Augustine - You heretics are all guilty and wicked by the crime of schism. From this most heinous sacrilege not one of you can say he is innocent. ("Contra Epistolam Parmeniani," Bk. II, ch.2, no. 25; PL 44; idem, no.25).

St. Augustine - If anyone holds to a single heresy, he is not a Catholic. ("On Heresies," no.88; PL 42)

Tertullian: "Heretics do not have the same God, the same Christ as Catholics." (Patrolo-giae Cursus Completus: Series Graca, Fr. J. P. Migne, Paris: 1866, 1:1216)

St. Cyril of Jerusalem: " When you are travelling to other cities do not ask simpy where is the Dominicum, the House of the Lord; for the imious and heretical sects also designate their dens by this name; nor ask simply where is the Church, but where is the Catholic Church: because this is the proper name of this holy mother, the mother of all of us" - Catech. 18, 23

St. Peter Canisius: "Who is to be called a Christian? He who confesses the doctrine of Christ and His Church. Hence, he is truly a Christian thoroughly condemns and detests. the Jewish, Mohammedan, and the heretical cults and sects." (St. Canisius Catholic Cate-chism, Dillingen, 1560, Question no. 1)

Ven. Pope Pius IX - Protestantism is the Great Revolt against God.

Pope Innocent IV - Heretics are to be classed with thieves and murderers. ( "Ad Extirpanda," cf. ISABELLA OF SPAIN, Dr. Wm. Thos. Walsh, London: Sheed & Ward, 1935, p.239)

Pope St. Leo the Great - Therefore, let the blind and foolish subtlety of heretical impiety be despised. Whosoever continues in heresy is unpardonable, nor can he ever attain forgiveness. They are falling into that blasphemy which shall never be forgiven, neither in this world nor in the Judgment to come. (Leo the Great: Sermon 75, PL 54:400; SS vol.III p.44, no.4)

Pope Innocent IV - Those who have been detected even by slight proof to have deviated from the doctrine of the Catholic religion ought to fall under the classification of heretic and under the sentences operating against heretics. (THE REGISTERS OF INNOCENT IV, Berger, Paris: 1881)

St. Augustine: "Heretics worship a God who is a liar, and a Christ who is a liar." (Pa-trologiae Cursus Completus: Series Graca, Fr. J. P. Migne, Paris: 1866, 42:207)

Pope Leo XIII - "If anyone holds to one single one of these (heresies) he is not a Catholic."-- (from Encyclical Satis Cognitum:28)

Catechism of Trent - Against the First Commandment, all those sin who do not have faith. Such sinners are very numerous, for they include all who fall into heresy, all who reject what Holy Mother the Church proposes for our belief. ( CATECHISM OF THE COUNCIL OF TRENT FOR PARISH PRIESTS, trans. Frs. McHugh & Callan, OP, NY: Joseph Wagner, Inc., 1923pp. 361, 369).

Pope St. Gregory the Great - Anyone who says "I love God," and does not keep His commandments, is a liar. ("Homilies on the Gospels," II:30,)

St. Robert Bellarmine: "A manifest heretic is not a Christian, as is clearly taught by St. Cyprian, St. Athanasius, St. Augustine, St. Jerome, and others." ("On the Church Mili-tant")

St. Alphonsus Maria Liguori - These unfortunate people do not see that, in refusing to submit to the Church, they reduce themselves to believing in nothing. The so-called Reformers have revived ancient heresies, and have sought by false doctrines to destroy the faith of Jesus Christ, and, if possible, to bring all souls with themselves to eternal perdition. (AN EXPOSITION AND DEFENSE OF ALL THE POINTS OF FAITH DISCUSSED AND DEFINED BY THE SACRED COUNCIL OF TRENT, St. Alphonsus Maria Liguori, Dublin: James Duffy & Co., 1846 ch.168).

St. John Eudes - The greatest evil existing today is heresy, an infernal rage which hurls countless souls into eternal damnation. (LETTERS AND SHORTER WORKS, St. John Eudes, trans. Ruth Hauser, NY Kenedy & Sons, 1948 p.55).

St. Bridget of Sweden: There is only one Christian faith, that is: Catholic. (Book of Reve-lations, St. Bridget of Sweden, ed. Cardinal John Torquemada, Rome: 1488)

St. Edmund Campion - What is the use of fighting for many articles of the faith, and to perish for the doubting of a few? He believes no one article of faith who refuses to believe any single one. (LETTERS FROM THE SAINTS, Fr. Claude Williamson, London: Wyman & Sons, 1948 p.176).

St. Catherine of Siena - What shows me that your life is badly governed? The poison of heresy! You have deserted the light and gone into darkness! I beg that you delay no more, nor kick against the prick of conscience which I know is perpetually tormenting you. Return, return, and do not wait for the rod of justice. For our faults do not pass unpunished, especially those committed against Holy Church. (READINGS IN CHURCH HISTORY, Fr. Colman Barry, OSB, Westminster, MD: The Newman Press, 1965 vol.I, p.477-479).

St. Frances Xavier - Many Protestants have almost the same practices as we, only they do not submit to the Holy Father and attach themselves to the true Ark of Salvation. They do not want to become Catholics and unite themselves under the banner of truth wherein alone there is true salvation. Of what avail is it, children, if Protestants lead naturally pure, honest lives, yet lack the Holy Ghost? They may well say: "We do no harm; we lead good lives"; but, if they do not enter the true fold of Christ, all their protestations are in vain. (St. Frances Xavier Cabrini, TRAVELS, pp.84, 71).

St. Peter Julian Eymard - People often say, "It is better to be a good Protestant than a bad Catholic." That is not true! That would mean that one could be saved without the true faith. No. A bad Catholic remains a child of the family, although a prodigal; and however great a sinner he may be, he still has a right to mercy. Through his faith, a bad Catholic is nearer to God than a Protestant, for he is a member of the household, whereas the heretic is not. And how hard it is to make him become one! (THE REAL PRESENCE, NY: Blessed Sacrament Fathers, 1938, p.245).

Fr. Michael Müller, C.SS.R., "The Catholic Dogma," 1888: "What Protestant Belief In Christ is - .(Protestants) never had any divine faith in Christ. 'He who does not believe all that Christ has taught,' says St. Ambrose, 'denies Christ himself.' (In Luc. c. 9.) 'It is absurd for a heretic,' says St. Thomas Aquinas, 'to assert that he believes in Jesus Christ. To believe in a man is to give our full assent to his word and to all he teaches. True faith, therefore, is absolute belief in Jesus Christ and in all he has taught. Hence he who does not adhere to all that Jesus Christ has prescribed for our salvation has no more the doc-trine of Jesus Christ and of his Church, than the Pagans, Jews and Turk's have.' 'He is' says Jesus Christ, 'a heathen and publican.'"

Those who turn aside unto deceits, the Lord shall number with the workers of iniquity. Thou art a God Who hatest all the workers of iniquity: Thou wilt destroy all who speak a lie. (Psalm 124:5; 5:7)