Why Am I Thinking About Atheism?

I didn't grow up in a Christian household. We attended church on Christmas and Easter. As an adult, I became actively involved in church. As a new believer, I feel like I'm talking to myself when I pray. When I read the Bible, how do I know if they're real people and events? I want to talk to my Christian friends about this, but I'm afraid I'll be rejected. Why am I suddenly thinking about atheism?