I know this is a little out of left field but I couldn't understand why anyone was Atheist until I read The Demon Haunted World by Carl Sagan... quickly followed by The Selfish Gene by Richard Dawkins. Those two books together crystallized in me what it could mean to have a world view absent of supernatural forces.
As a companion to this, I grew up somewhat militantly Atheist (and consumed Dawkins like skittles), and had a very hard time accepting faith in a reasonably way until I read Maps of Meaning: The Architecture of Belief by Jordan Peterson. I know he's unfortunately become quite the provocateur, but that first book is worth a read, and crystallized to me what it could mean to have a world view with a supernatural force.
It made me realize that viewing the world through a narrative structure was far more interesting than the materialist portrayal of the New atheists.