Hypocrisy and abuse are no proof of error; they are proof of weak, sinful human beings. To point to hypocrisy or abuse in argumentation is an ad hominem fallacy, a fallacy that many dissenters to and enemies of the Catholic Church employ over and over again.
The distinction between abstract/absolute ideas and and individual actions is crucial to the acceptance of the Catholic faith (or any belief system for that matter). Yet many people are unable to understand or unwilling to accept this crucial distinction.
If the saints of the Church are not proof of the truth of Catholic doctrines, then neither are corrupt clergy proof of the error of Catholic doctrines. Doctrinal truth is not dependent on the character of individual men and women but upon the Holy Spirit acting through the offices of pope and bishop, who declare what is true doctrine (1 Tim 4:11, 6:2-5; Titus 1:13, 2:1, 15).
St. Peter and St. Paul were both sinners and hypocrites, as Scripture tells us. Peter is rebuked by Paul because of Peter’s hypocrisy in declaring no food unclean and circumcision unnecessary at the Council of Jerusalem yet drawing away from the Gentiles in fear of “the circumcision party” (Gal 2:12-14; Act 11:1-18, 15:6-14). Paul too showed himself to be a hypocrite to Christian teaching in his trivial quarrel with Barnabas over John Mark and in his other sins (Act 15:37-40; Rom 7:14-25).
Did the sins of Peter and Paul make their teachings any less true? Of course not!
Truth does not cease being truth just because an individual acts sinfully and in contradiction to truth that he knows to be true and has preached to be true. This truth about truth is true even in the case of popes, bishops, and priests. The sins of clergy or individual lay Catholics have not and cannot change Catholic truths, which Catholic clergy, esp. the popes, have merely preserved and passed on since the time of the original apostles.
So it doesn’t matter how many times you bring up the Crusades, Inquisition, adulterous popes and clergy, individual Catholics complicit in the Holocaust, leftist Catholics like Nancy Pelosi, pedophile priests, abuse of annulments, or any other scandal, whether real or false: NONE of these things have changed Catholic doctrine over time. Nor could they.
That this is an historical fact is a tangible testament to the unique work and presence of the Holy Spirit in the Roman Catholic Church, which has preserved correct doctrine without change for about 2000 years. Jesus was not lying when He said that His Church built upon the Rock of Cephas would not fail.
The Roman Catholic Church is holy, not because its leaders and members have been or are sinless but because by the power of the Holy Spirit it possesses certain and true doctrines without error, doctrines that can be traced historically through Church history back to the beginning. “If the root is holy, so are the branches” (Rom 11:16).