1917 Code of Canon Law, Canon 823: “Mass may not be said in churches of heretics or schismatics, even though they were in the past properly consecrated or blessed.”
1917 Code of Canon Law, Canon 1258.1: “It is unlawful for the faithful to assist in any active manner, or to take part in the sacred services of non-Catholics.”
Pope Pius XI, Mortalium animos (# 10): “So, Venerable Brethren, it is clear why this Apostolic See has never allowed its subjects to take part in the assemblies of non-Catholics:for the union of Christians can onlybe promoted by promoting the return to the one true Church of Christ of those who are separated from it, for in the past they have unhappily left it. To the one true Church of Christ, we say, which is visible to all,and which is to remain, according to the will of its Author, exactly the same as He instituted it.”
For people then to claim (in spite of all the quotations above saying otherwise) that one may pray at heretical churches or receive the sacraments from them or that an assembly presided over by heretics or an assembly that prays in communion with other heretics, to somehow be the Church of God or the Church of Catholics, is simply to deny God’s revealed infallible truth.
