I just watched a video that asks the question "Why are so many people leaving the Church?"
It is because organized Christian based religion tells you what to believe, that you must believe it, and you must not question it. It goes on to list all the reasons why churches claim people are leaving and debunks them all. The only reason that holds water is that people are examining their faith and find it empty.
I left Jehovah's Witnesses after being born in and staying in until my 30s. Then I was a nihilistic antitheist. I began to return to a generic Christianity after 10 years of antitheism. Soon, after more research, I came to realize that the Bible (with the exception of some of the Gospels) was a horrible book and Judeo-Christian faith makes no sense.