The Authentic Teaching of the Catholic Church on Interfaith Relations
«If thy brother the son of thy mother, or thy son, or daughter, or thy wife that is in thy bosom, or thy friend, whom thou lovest as thy own soul, would persuade thee secretly, saying: “Let us go, and serve strange gods, which thou knowest not, nor thy fathers, of all the nations round about, that are near or afar off, from one end of the earth to the other,” consent not to him, hear him not, neither let thy eye spare him to pity and conceal him. But thou shalt presently put him to death. Let thy hand be first upon him, and afterwards the hands of all the people. With stones shall he be stoned to death: because he would have withdrawn thee from the Lord thy God, who brought thee out of the land of Egypt, from the house of bondage.» (Deuteronomy XIII: 6-10).
From
Mortalium Animos
On Fostering True Religious Unity
Encyclical Of Pope Pius XI
January 6, AD 1928
2) ... Assured that there exist few men who are entirely devoid of the religious sense, [some] seem to ground on this belief a hope that all nations, while differing indeed in religious matters, may yet without great difficulty be brought to fraternal agreement on certain points of doctrine which will form a common basis of the spiritual life. With this object congresses, meetings, and addresses are arranged, attended by a large concourse of hearers, where all without distinction, unbelievers of every kind as well as Christians, even those who unhappily have rejected Christ and denied His divine nature or mission, are invited to join in the discussion. Now, such efforts can meet with no kind of approval among Catholics. They presuppose the erroneous view that all religions are more or less good and praiseworthy, inasmuch as all give expression, under various forms, to that innate sense which leads men to God and to the obedient acknowledgment of His rule. Those who hold such a view are not only in error; they distort the true idea of religion, and thus reject it, falling gradually into naturalism and atheism. To favor this opinion, therefore, and to encourage such undertakings is tantamount to abandoning the religion revealed by God.
5. God, the Creator of all things, made us that we might know Him and serve Him; to our service, therefore, He has a full right. He might indeed have been contented to prescribe for man's government the natural law alone, that is, the law which in creation He has written upon man's heart, and have regulated the progress of that law by His ordinary Providence. He willed, however, to make positive laws which we should obey, and progressively, from the beginnings of the human race until the coming and preaching of Jesus Christ, He Himself taught mankind the duties which a rational creature owes to His Creator. "God, Who at sundry times and in diverse manners spoke in times past to the fathers by the prophets, last of all in these days hath spoken to us by His Son" (Heb. i. 1, seq.). Evidently, therefore, no religion can be true save that which rests upon the revelation of God, a revelation begun from the very first, continued under the Old Law, and brought to completion by Jesus Christ Himself under the New. Now, if God has spoken--and it is historically certain that He has in fact spoken--then it is clearly man's duty implicitly to believe His revelation and to obey His commands. That we might rightly do both, for the glory of God and for our own salvation, the only-begotten Son of God founded His Church on earth. None, we think, of those who claim to be Christians will deny that a Church, and one sole Church, was founded by Christ.
9. This being so, it is clear that the Apostolic See can by no means take part in these assemblies. nor is it in any way lawful for Catholics to give to such enterprises their encouragement or support. If they did so, they would be giving countenance to a false Christianity quite alien to the one Church of Christ. Shall we commit the iniquity of suffering the truth, the truth revealed by God, to be made a subject for compromise? For it is indeed a question of defending revealed truth. Jesus Christ sent His Apostles into the whole world to declare the faith of the Gospel to every nation, and, to save them from error, He willed that the Holy Ghost should first teach them all truth. Has this doctrine, then, disappeared, or at any time been obscured, in the Church of which God Himself is the ruler and guardian? Our Redeemer plainly said that His Gospel was intended not only for the apostolic age but for all time. Can the object of faith, then, have become in the process of time so dim and uncertain that today we must tolerate contradictory opinions? If this were so, then we should have to admit that the coming of the Holy Ghost upon the Apostles, the perpetual indwelling of the same Spirit in the Church, nay, the very preaching of Jesus Christ, have centuries ago lost their efficacy and value. To affirm this would be blasphemy. The only-begotten Son of God not only bade His representatives to teach all nations; He also obliged all men to give credence to whatever was taught them by "witnesses preordained by God" (Acts x. 41). Moreover, He enforced His command with this sanction: "He that believeth and is baptized shall be saved; he that believeth not shall be condemned" (Mark xvi. 16). These two commands, the one to teach, the other to believe for salvation, must be obeyed. But they cannot even be understood unless the Church proposes an inviolate and clear teaching, and in proposing it is immune from all danger of error. It is also false to say that. although the deposit of truth does indeed exist, yet it is to be found only with such laborious effort and after such lengthy study and discussion, that a man's life is hardly long enough for its discovery and attainment. This would be equivalent to saying that the most merciful God spoke through the prophets and through His only-begotten Son merely in order that some few men, and those advanced in years, might learn what He had revealed, and not in order to inculcate a doctrine of faith and morals by which man should be guided throughout the whole of his life.
10. These pan- Christians who strive for the union of the Churches would appear to pursue the noblest of ideals in promoting charity among all Christians. But how should charity tend to the detriment of faith? Everyone knows that John himself, the Apostle of love, who seems in his Gospel to have revealed the secrets of the Sacred Heart of Jesus, and who never ceased to impress upon the memory of his disciples the new commandment "to love one another," nevertheless strictly forbade any intercourse with those who professed a mutilated and corrupt form of Christ's teaching: "If any man come to you, and bring not this doctrine, receive him not into the house, nor say to him, God speed you" (2 John 10).
11. Therefore, since the foundation of charity is faith pure and inviolate, it is chiefly by the bond of one faith that the disciples of Christ are to be united. A federation of Christians, then, is inconceivable in which each member retains his own opinions and private judgment in matters of faith, even though they differ from the opinions of all the rest. How can men with opposite convictions belong to one and the same Federation of the faithful: those who accept sacred Tradition as a source of revelation and those who reject it; those who recognize as divinely constituted the hierarchy of bishops, priests, and ministers in the Church, and those who regard it as gradually introduced to suit the conditions of the time; those who adore Christ really present in the Most Holy Eucharist through that wonderful conversion of the bread and wine, transubstantiation, and those who assert that the body of Christ is there only by faith or by the signification and virtue of the sacrament; those who in the Eucharist recognize both sacrament and sacrifice, and those who say that it is nothing more than the memorial of the Lord's supper; those who think it right and useful to pray to the Saints reigning with Christ, especially to Mary the Mother of God, and to venerate their images, and those who refuse such veneration as derogatory to the honor due Jesus Christ, "the one mediator of God and men" (cf. I Tim.ii.5)?
12. How so great a variety of opinions can clear the way for the unity of the Church, We know not. That unity can arise only from one teaching authority, one law of belief, and one faith of Christians. But we do know that from such a state of affairs it is but an easy step to the neglect of religion or "indifferentism," and to the error of the modernists, who hold that dogmatic truth is not absolute but relative, that is, that it changes according to the varying necessities of time and place and the varying tendencies of the mind; that it is not contained in an immutable tradition, but can be altered to suit the needs of human life.
18. You, Venerable Brethren, know how dear to Our heart is this desire, and We wish that Our children also should know, not only those belonging to the Catholic fold, but also those separated from Us. If these will humbly beg light from heaven. there is no doubt but that they will recognize the one true Church of Jesus Christ, and entering therein, will at last be united with Us in perfect charity. In the hope of this fulfillment, and as a pledge of Our fatherly goodwill, We impart most lovingly to you, Venerable Brethren, and to your clergy and people, the Apostolic Benediction.
Given at Rome, at Saint Peter's, on the 6th day of January, on the Feast of the Epiphany of Jesus Christ, our Lord, in the year 1928, and the sixth year of Our Pontificate.
+ PIUS P.P. XI
