There are a lot of reasons as to why people rebel or turn against their religion and beliefs. One reason is when a parent or guardian forces you to do something you didn't want to do. Churches are an great example of this, people get baptized all the time. Normally, the kid's parents either force them to when they are older or already decide for them when they are a baby to be baptized. This doesn't let them make their own decisions and when it happens over and over again they start to rebel. They refuse to go to church and start questioning in themselves what they believe. The reason why is because these parents have made decisions for them their whole life and when they crack they don't know what to believe. That's when the rebel starts to happen and they do the complete opposite of what they have been learning. Another reason is probably a traumatic moment in their life which caused them to not want to believe something or stop what ever religion they are doing. I'm going to use a Church again as an example. Let's just say a shooting happens and people are praying for God's help, someones brother dies. They might stop believing in God or not go to Church. They might even start up a shooting at some other Church.
I dont know i kinda tried i think its ok but who knows.. :'(