If the devil has infiltrated the Church, he didn’t do it with a secret underground network of villains bent on destroying the Church. He did it by exploiting Catholics. The devil has indeed breached our walls, but he did it by infecting some of the faithful with the disease of secularism. Secularism is behind every imbalance and every problem we see in the Church.
Your comment about being an example to young people reminded me of some things that happened this evening at a (Novus Ordo) Mass I attended. I am still one of the few who kneel after the Agnus Dei, but a young man who was on the same pew as me was first standing like the rest, but then he knelt down. After Mass I was in the vestibule and struck up a conversation with a young lady. I mentioned I was a convert. She asked why. I told her it was the Bible that converted me. I told her some of the verses that were key, and she was really interested. I thought I was so old that young people wouldn't care to listen. I guess I was wrong.