I'm actually quite interested in this story. The in God we trust part was really interesting.
But I want to see where it goes. If Satan turns out to be the good guy, it's lame, but it doesn't look like it's going that way. So we either have the protagonist getting led further and further down the wrong path till he does something really atrocious, but I don't see that happening so much because they didn't establish anything good now that he'd regret destroying.
So we have antsy confrontations with angels, all trying to reach out to him and he keeps on rejecting him until when it comes to the last coin toss he tears himself free, foils Satan and does a whole lot of good as he's taken up to heaven. Maybe even a 'this was all part of the plan' thing going on. (Not his plan, God's plan). That'd be pretty cool.
Else he's on God's side subverting Satan from the inside. It's got potential but it'd fall flat for me in the end because it makes signing a contract with the opposite number not much of a deal, which would devalue Satan in the story
EDIT: No, doing some research, they went for lame 'Dark Eaville, is on a mission to stop Heaven's agency and bring back the delicate balance between good and evil.' That's even worse than I thought. I mean for one, that name is ridiculously stupid and secondly, who on earth wants to balance good and evil?? That's worse than bringing balance to the force. Oh gee things are really good at the moment, I do wish there was a bit of torturing and soul destorying to balance out this nice time I'm having