I was a Christian well into my teens. I was raised on Jesus and God, the idea that they weren't real never even occurred to me. Literally everyone I knew, to the best of my knowledge, believed. After I read the Bible through a couple of times (intended as an act of devotion), I didn't believe in Pentecostalism or Christianity anymore, but it still didn't occur to me that God might not be real. I just thought the Hebrews weren't actually in contact with him/her/it/them. It took many more years of inquiry and education before I noticed I had let go of God at some point.
I'm not anti-Christian. I'm anti-stupid.