Christian books, movies, or methods to help reassure my faith?

I need something that will restore my faith or help me understand more.
I’m a teenager and I want to believe in God, I really do, and I believe in him, I just need more reassurance. I’m sure everyone goes through this at sometime in their life, I just want something to "cement" my faith.

I don’t really know how to explain, but anything that you think would be good for me to check out at the bookstore would be great. Thank you.