If someone asks you if you're a god, you. Say. YES!
And in some RPGs, you certainly can end up with a character that's partly divine to all the way divine. But unless you're all-powerful (and I don't think a lot of GMs are going to be like, "oh yeah, you can just do whatever, no consequences, no roll needed. Just go right on ahead."), you're going to need implements to help you out in your god-duties. That's where Divine Instruments of Fate, from Third Eye Games, comes in.
The sourcebook was originally written for Part-Time Gods, but it has since been adapted to the Fate system, for those of you that enjoy that. The book has such relics as the Mask of Many Faces, Timepiece of Chronos, and the Horn of Plenty, with which you can complete your various quests. Also, being (at least part) deity, you'll need followers and those followers will need a place to worship, so there's rules for temples and other such items so you can grow your following.