Why do we believe in God?

I posted a sign written in pink highlighter that asked, "Why do we believe in God?". The brainstorm of an answer to this question came to me about a week ago while I was calling on Him. At the time I was in need, a deep sincere need that could only be understood from a view outside of myself. So I called God's name and instantly felt peace. To me that peace came from knowing that I wasn't alone, and that I could look both inside and outside of my situation for solutions...