The thing is that you really have to know and understand George's history and journey to understand his conversion.
When he joined the Beatles and they became the biggest rock band ever, all four let it go to their heads with drugs, sex, and all other vices you could possibly think of. There was no quiet alone time when you are a Beatle. The first song George recorded with the Beatles as lead singer was a song he wrote called "Don't Bother Me" about how there was no room for alone time and there was no privacy. He really hated that. Add that with all the sex, drugs, and other vices, he was living life on the fast lane. Then he took a trip to India and met Swamis and learned about Hinduism there and he found that this religion helped him. He found something he didn't have for a long time--peace and happiness.
From what I've seen, people who live sinful lives and go off the edge and then go back to religion, go back to the religion they find when they are off the edge. For example, Glenn Beck was an big alcoholic and into all sort of things, but he met his wife and found the Mormon church. Do I agree with the LDS church? No. But it was able to provide him with what he needed and he is better off then when he was an alcoholic.
Fr. Corapi is a case where he came back to his original faith, but unfortunately this isn't always the case and we have to accept that.
I'm glad George found his faith, even if it wasn't in the Church, because he became a better person than he was before it. And because of it he wrote some of the greatest songs I've ever heard (for these songs, look at my links above).