Orange and blue cover book about a teen boy who dies and gets caught between Heaven and Hell

I read this book in middle school (2005-06, though I’m not sure when it was written) but I cannot think of the name or author for the life of me.

The main character is a little bit of a shit and there’s some confusion over whether he should go to heaven or hell (or maybe there’s a holdup in the bureaucracy?) so he goes on a bunch of side quests toward redemption with Beelzebub and St. Peter popping in and out of the story