|Tilman Riemenschneider, The Last Supper, detail showing St. John the Evangelist|
In his encyclical Mortalium Animos, Pope Pius XI makes notable appeal to the teaching of the Apostle and Evangelist John to distinguish between true and false charity toward non-Catholic Christians:
These pan-Christians who turn their minds to uniting the churches seem, indeed, to pursue the noblest of ideas in promoting charity among all Christians: nevertheless how does it happen that this charity tends to injure faith? Everyone knows that John himself, the Apostle of love, who seems to reveal in his Gospel the secrets of the Sacred Heart of Jesus, and who never ceased to impress on the memories of his followers the new commandment "Love one another," altogether forbade any intercourse with those who professed a mutilated and corrupt version 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." For which reason, since charity is based on a complete and sincere faith, the disciples of Christ must be united principally by the bond of one faith. Who then can conceive a Christian Federation, the members of which retain each his own opinions and private judgment, even in matters which concern the object of faith, even though they be repugnant to the opinions of the rest? And in what manner, We ask, can men who follow contrary opinions, belong to one and the same Federation of the faithful? For example, those who affirm, and those who deny that sacred Tradition is a true fount of divine Revelation; those who hold that an ecclesiastical hierarchy, made up of bishops, priests and ministers, has been divinely constituted, and those who assert that it has been brought in little by little in accordance with the conditions of the time; those who adore Christ really present in the Most Holy Eucharist through that marvelous conversion of the bread and wine, which is called transubstantiation, and those who affirm that Christ is present only by faith or by the signification and virtue of the Sacrament; those who in the Eucharist recognize the nature both of a sacrament and of a sacrifice, and those who say that it is nothing more than the memorial or commemoration of the Lord's Supper; those who believe it to be good and useful to invoke by prayer the Saints reigning with Christ, especially Mary the Mother of God, and to venerate their images, and those who urge that such a veneration is not to be made use of, for it is contrary to the honor due to Jesus Christ, "the one mediator of God and men." How so great a variety of opinions can make the way clear to effect the unity of the Church We know not; that unity can only arise from one teaching authority, one law of belief and one faith of Christians. But We do know that from this it is an easy step to the neglect of religion or indifferentism and to modernism, as they call it. (¶ 9)
No one understands charity better than St. John, but he understood that the theological virtue of charity must be founded on the theological virtue of faith, and therefore anything that undermines the faith of necessity undermines charity. And therefore he commands us to avoid contact with those who would undermine the faith.
In general one can see that love necessarily cause the one loving to hate anything which threatens to destroy what is loved. Thus, since we naturally love health, therefore we naturally hate disease; since we naturally love life, we naturally hate anything that destroys our lives, and so on. And charity is no exception the supernatural love of God above all things necessarily implies hatred of sin, which is directly opposed to that charity, and error which is opposed to the faith on which it is founded.
But ecumenists have difficulty seeing this. Even if they would perhaps hesitate to use such strong words, the would probably agree with the non-Catholic New Testament scholar Gerd Lüdemann’s judgement on St. John, in his critique of Pope Benedict XVI’s Deus Caritas Est:
[The] Johannine communities fell far short of exhibiting the love that [Pope Benedict XVI] recommends to the contemporary church. For not only does the First Letter of John—from which the encyclical takes its theme and exhortation—restrict brotherhood to those of orthodox belief, but the Second Letter of John, which quite predictably is not mentioned in the encyclical, takes the same approach and pushes it even further. In verses 9 through 11 of this very brief letter, its author, who identifies himself only as ‘the Elder,’ commands the community to receive into their homes only those brothers who confess Christ’s coming in the flesh. Any present or former brothers who have a different opinion concerning Christ’s incarnation should be spurned. Indeed, “John” forbids the members of his communities even to greet them. He deems this precautionary measure necessary, lest the community of right belief become infected by the evil doctrines and consequent guilt of its dissident brothers. How strange it is to encounter such harsh and hate-filled expostulations in a letter overflowing with assurances of mutual love and attesting to a community’s unanimous recognition of sacred truth!
Lüdemann’s reasoning is precisely the sort of thing that one is likely to hear from contemporary ecumenists. And the reason is clear: they are not motivated by the supernatural virtue of charity, founded on the one true faith, but rather by a vague benevolence, founded on modernism and indifferentism. And like every kind of love, this vague benevolence causes a hatred of everything that threatens the object of love; they do not (like St. John) hate heresy, rather they hate “fanaticism” and “fundamentalism.” In other words they hate the perennial claim of the Catholic Church to teach the truth.