It’s simple. You believe that Jesus was telling the truth when He told Peter: You are Peter and on this rock I will build my Church. The gates of Hell will not prevail against it. You believe that His Truth, His Keys to the Kingdom and His authority to loose and to bind or you don’t.
If you DO believe it, then stay, get involved and make change. You are not impotent in the life of the Church. You can be part of the change the Church needs if you so choose. If you do not believe the words of our Lord to Peter, then you are already out of the Church.
The people of the Church will always be fallible. Sometimes, in little ways. Other times, as now and even more so in prior times, in unspeakable and deeply disturbing ways. If every lay Catholic, priest, bishop and pope were corrupt, it would not change one letter of Christ’s teachings and His salvation through the sacraments.
Simple does NOT mean easy. You will not win any popularity contests staying faithful to the teachings of the Church. Mild name calling is probably the least of what you will hear leveled against you. You will probably feel ashamed, shocked, disgusted and disturbed by the actions of Church leaders. You will need strength and courage to go against the tide of popular opinion. It is worth it to have life in Him.