With the confidence born of divine faith and true ecclesiastical authority, Pope Leo XIII was able, in 1899, to diagnose one of the characteristic errors of modern times and the only proper response a Catholic can make to it:
The underlying principle of these new opinions [he is speaking of Americanism] is that, in order the more easily to attract those who differ from her, the Church should shape her teachings more in accord with the spirit of the age and relax some of her ancient severity and make some concessions to new opinions. Many think that these concessions should be made not only in regard to ways of living, but even in regard to doctrines which belong to the deposit of the faith. They contend that it would be opportune, in order to gain those who differ from us, to omit certain points of her teaching which are of lesser importance, and to tone down the meaning which the Church has always attached to them. It does not need many words, beloved son, to prove the falsity of these ideas if the nature and origin of the doctrine which the Church proposes are recalled to mind. … Let it be far from anyone’s mind to suppress for any reason any doctrine that has been handed down. Such a policy would tend rather to separate Catholics from the Church than to bring in those who differ. (Testem Benevolentiae)
Can papal writing get clearer than this? That which belongs to the doctrine of faith and morals handed down by the Church is immutable, unassailable, always relevant, always required; it is from God as its author, for God as its final end, within man’s power by the help of God’s grace—and by it every man will be judged, for God is no respecter of persons.
