In 1972 I enrolled in a Bible college sponsored by "The World's Largest Sunday School," which was running 8,000 in attendance at the time. When I graduated five years later, they were averaging 40,000. While there, I worked for two years under the pastor's son, an extremely successful youth director. Unknown to most of us, he was actively fornicating with teen-agers. In later years, he aggressively sought out the wives of Godly deacons, and it is conservative to say that he committed immorality with several dozen women.
After he got caught, the church proclaimed that he had been "restored," and they got him some important preaching opportunities. He went through about four churches, getting caught in immorality in all four, in one case actually causing the church to decline to the point that it merged into another one. He got "restored" a few more times, and is currently musing on the internet about the hypocrisy of his critics.
I knew back then that he hadn't been restored, and I knew when I found him on the web that he is a hypocrite today, and I was right both times (He's currently pushing a crooked work at home scheme). How do you know if a fallen preacher's repentance is genuine? I'm going to explain that.