The US Communist Party infiltrated American seminaries with many thousands of agents. The same happened in all other parts of the world. Despite this tragedy, Church doctrine remains pure and undefiled. How do you account for this miracle other than by divine protection?
Threats of force and hellfire and brimstone..... The inquisitions ordered by those who claim to be Christ's representative on earth. Not very Christlike by all accounts.
Catholic tradition remaining *pure* means nothing. It certainly doesn't mean it's right or true. All it means is that it hasn't changed from what was originally established.
And even that's debatable based on some of the stuff I've seen posted about the church fathers on these threads.