Ex-Christian?
I was looking for a story to illustrate "disappointment" and google led me to "ex-Christian", a site of "de-conversion" stories.
Some sad stuff there.
It's worth looking at a because there are some valid critiques and lessons to be learned. Clearly most of the stories are from the USA, and are perhaps as much a rejection of a cultural Christianity. And some will always chose to leave.
But we've much to learn about the way of Jesus I think.