Divine Obligations

Gods owe so many souls to the Prime Material. They collect them post-mortem, then essentially ante then back to reality, gambling to win more. Those souls are payment, kind of, for divine status. If you can't pay up, you may be bumped down a level. If there's an open spot, you can pay more to move up. It's all a great cycle that works on conversion and right action and all that - the collecting of more worshippers.