"Is it permitted for Catholics to be present at, or to take part in, conventions, gatherings, meetings, or societies of non-Catholics which aim to associate together under a single agreement everyone who, in any way, lays claim to the name Christian? In the negative!... It is clear, therefore, why this Apostolic See has never allowed its subjects to take part in the assemblies of non-Catholics, There is only one wav in which the unity of Christians may be fostered, and that is by furthering the return to the one true Church of Christ those who are separated from her. " (Pope Pius XI, Mortalium Animos). Comment: Anyone who believes it is all right to go to ecumenical services during Thanksgiving and Lent, and any other time, needs to read that encyclical For some 1920 years (33AD to 1958 AD), the Church has been vigilant on warning her children to stay away from such gatherings.

The 1917 Code of Canon Law states: that: " It is not permitted at all for the faithful to assist in any active manner at or to have any part in the worship of non-Catholics." [Canon 1258]

A true believer is a Catholic who believes what the Church teaches. In the early Church, were the souls who followed Christ called Christians or Protestants? Christians: "At Antioch the disciples were fist named Christians" (Acts 11:26). Were there any Protestants in Christ's time concerning His doctrines? Yes. When our Lord first taught that we must eat His flesh and drink his blood for the life of our souls. the first Protestants - the Jews - said, "how can this man give us His flesh to eat?" (.St. John 6:53). And Jesus reaffirmed most solemnly, "Amen,  Amen, say unto you: except you eat the flesh of the ,Son. of Man and drink His blood, You shall not have life in you (vs. 54). So. were these first Protestants - who rejected the doctrine of the true presence - united to Christ or did they walk no more with Him? Scripture says, "After this many of His disciples went back and walked no more with Him" (vs. 67). You see? A rejection of Christ's doctrine is a rejection of Christ. These disciples - who walked no more with Him - apparently believed in Him at one time, but when they rejected His teaching, they rejected Him; does anyone truly think they were saved? We must do more than believe in Him, we must also follow what He taught: "And why call ye Me Lord, Lord, and do not the things which I say?"

Nowadays you have Catholic clergy going to Protestant churches giving talks. Origin expressly states "If you eat the words of God in the Church, and also eat them in the ,synagogue of the Jews, you transgress the commandment which says: In one house shall it be eaten "{Ex. 12:46}

"How does a Catholic sin against faith? A Catholic sins against Faith by Apostasy, heresy, indifferentism and by taking part in non-Catholic worship." (Catechism of the Council of Trent, Catechism of Pope St. Pius X and The Baltimore Catechism).

"For if they have doctrines opposed to ours, it is not fitting to be mixed up with them for this cause alone... what do you say? 'There faith is the same; these men are orthodox?' why, then, are they not with us?"  - St. John Chrysostom

"St. Anthony the Abbot would not speak to a heretic, except to exhort him to the true faith; and he drove all heretics from his mountain, calling them venomous serpents." - St. Athanasius on the life of St. Anthony the Hermit,

"It is therefore unlawful, and a profanation, and an act the punishment of which is death, to love to associate with unholy heretics, and to unite oneself to their communion" – St.. Cyril of Alexandri.

"You help the ungodly, and you are joined in friendship with those who hate the Lord; and therefore you did indeed deserve the wrath of the Lord -  II Paralipomenon 19:2.

“Saint Peter and Paul have loathed heretics, and in their Epistles have warned us to avoid them” – St. Cyprian

St. Athanasius went as far as refusing the name of Christian to those who left the Church as he openly affirms "Those who go off to heretics, and all who leave the Church for heresy, abandon the name of Christ. Those who call these men "Christians" are in griev-ous error, since they neither understand Scripture at all nor the faith which it contains." - Discourse Against the Arians," Bk. I, ch.1, no. 1, PG 26:11

Saint Jerome rightly pointed regarding the sacrifices of heretics that: "God hates the sacrifices of these [ i.e., heretics] and pushes them away from Himself, and whenever they come together in the name of the Lord, He abhors their stench, and holds his nose." - In Amos, V: 22, P.L. 25, 1033-1034.

The same idea is clearly expressed by St. Cyprian who states that "The schismatic dares to set up an altar and to profane the truth of the divine Victim by means of false sacrifices.” -De Unitate Ecclesiæ, c. 17. P.L. 4, 513.

"St. John, the disciple of the Lord, (the Apostle of love), going to bathe at Ephesus, and .finding Cerinthus inside, rushed out ()f the bathhouse without bathing, shouting: 'Let us fly, lest even the bath-house fall down, for Cerinthas, the enemy of truth, is inside!' And Polycarp himself replied to Marcion, who met him on one occasion asking: 'Do you know me?' '1 do know you', replied Polycarp, 'I know you to be the .first born of Satan!' Such was the horror which the Apostles and their disciples had against holding even verbal , communication with any corrupters of the truth"   - St.  Irenaeus of Lyon, Against the Heresies, book III.

In respect to their guilt whereby they are opposed to God, all sinners are to be hated, even one's father or mother or kindred, according to St. Luke 14:26. For it is our duty to hate in the sinner his being a sinner" - St. Thomas Aquinas, (STL 11-11, Q. 25 Art 6.).

"If any ecclesiastic or layman shall go into the synagogue of the Jews or to the meeting-houses of the heretics to join in prayer with them, let them be deposed and deprived of communion If any Bishops or Priest or Deacon shall join in prayer with heretics, let him be suspended from Communion" - III Council of Constantinople.

Pius XI in dealing with this issue that was so vehement in his own day had only the following to say "Certainly such movements as these cannot gain the approval of Catholics. They are founded upon the false opinions of those who say that, since all religions equally unfold and signify- though not in the same way - the native, inborn feeling in us all through which we are borne toward God and humbly recognize His rule, therefore, all religions are more or less good and praiseworthy. The followers of this theory are not only deceived and mistaken, but since they repudiate the true religion by attacking it in its very essence, they move step by step toward naturalism and atheism. Hence it clearly follows that anyone who gives assent to such theories and undertakings utterly abandons divinely revealed religion. " (Mortalium Animos)

"Cut off from the Church: One must neither pray nor sing psalms with those who are cut off from the communion of the Church, whether clergy or layman: let him be excommunicated" - Council of Carthage.

"No one shall pray in common with heretics and schismatics" - Council of Laodicea.

"I will not pray with you, nor shall you pray with me; neither will I  say 'Amen' to your prayers, nor shall you to mine"  - St. Margaret Clitherow

"These men are Protestants; they are heretics. Have nothing to do with them.! -  St. Anthony Alary Claret, The Modern Apostles.

"It is not lawful to go to the Protestant Church" – St.  John Rigby

"We decree that those who give credence to the teachings of heretics, as well as those who receive, defend, or patronize them, are excommunicated... If anyone refuses to avoid such accomplices after they have been ostracized by the Church, let them also be excommunicated" - IV Lateran Council

This is the voice of the Church. Let him who fears for his salvation hear the voice of the Church or be as the heathen, "If he will not hear the Church, let him be to thee as the heathen and the publican" – Matt 18:17

Our Lord Said to St. Paul ' “I send you to the Gentiles to open their eyes, that they may turn from darkness to light and from the power of Satan to God, that they may receive forgiveness of sins by faith in Me” (Acts 26:18)

"Make no mistake, my brethren, they shall suffer everlasting punishment who endeavor to corrupt the Church of Christ. Whosoever sets at nought His doctrine shall go into hell, and so shall everyone who listens to him" – St. Ignatisus of Antioch.

"Do not treat with a man without religion. Give no heed to them in any matter of council" - Ecclus. 37: 12

A Protestant once approached St. John Vianney saying, 'though we are not together on earth, we shall be together in heaven'. The saint looked into the man's eyes and said gently: "As the tree leans, so the tree falls. If we do not live together on earth, we shall not live together in heaven. Death makes no change in that". The Protestant upon hearing these gentle words of the saint considered them, renounced his error, and became a Catholic.

A heretic is led by his own judgment rather than the teaching of the Church, and is lost" "A man that is a heretic... is subverted and sins, being condemned by his own judgment" (Titus 3: 10). Every man must be taught. Christ told His Apostles, the ministers of His Church: "Go and teach all nations (Matt 28: 1 9). He that believeth not, shall be condemned" (St. Matt 16: 16).

"Since these wretched souls will have to be separated from God and Heaven for all eternity because their place will be in hell, already here on earth they have to be separated from the company of Christ our Lord and His servants and hand-maids. Predestinated souls, you who are of God, cut yourselves adrift from those who are damning themselves.!"  - St. Louis De Monfort

Prayer of Pope Pius X: "Give thanks to God that He has made you a child of His Church which is always animated and governed by His Divine Spirit who was sent into the world on the day of Pentecost. Hear and follow the sovereign Pontiff, who teaches infallibly through the Holy Ghost and the Church, which is the pillar and ground of truth (1 Tim 3: J 5). Hold fast to her doctrines, maintain her cause, defend her rights. Live always as becomes a child of God and a member of the true Church of God, so that after this life, you may receive Heaven as your inheritance, Glory be to the Father, and to the Son, and to the Holy Ghost.! Amen"