The church teaches the gospel to children as fact before they're old enough to think for themselves. The church baptizes children before they're old enough to make an informed decision. The church discourages questioning of the church. Young people stay in the church more due to social pressure than religious conviction. Beyond the church, I have a list of things I don't like about religion in general.
Believers think that they're right and everyone else is wrong.
Religion causes wars, contention, and intolerance. Religion can separate people and families. It can be used to rationalize evils. Each religion rejects other religions. In my opinion, I would be better off with no religion at all.