Now, luckily, you can. http://www.universaldivinity.com/be-a-go
Sure... Anyone can climb up on their little rock, beat their tiny chest, and scream "I'm a god, dammit!" but that's hardly the same as being recognized as a living god - or saint, angel, etc. - by an actual, practiced religion.
Not only is this religion compatible with all other religions, it's the perfect religion for atheists, too... In Universal Divinity (Universalism), each member defines what concepts like "God" or "Saint" or "Moral" or "sin" means to them.
If you're also a Christian, consider that your God clearly believes in other gods - "Thou shalt have no other god before me" would sound pretty silly if he didn't - So, you can too. You just can't place any of them above Him. So, in your devotions, you simply define and understand that all these other gods come after the God of Isaac and Abraham.
If you're an atheist and don't believe in any "gods" that's fine too. Do you believe that people who do believe in gods should get special tax breaks and other privileges that you don't get? So, in your devotions, you decide that a "god" is some kind of special representative of the luck, karma, etc. of some thing or idea... No special powers, no spooky aspects, just someone to associate with something when the mood strikes you, and Shazam! You're "religious" too...
"Religion" being, in part, according the Oxford English Dictionary, "...a pursuit or interest followed with devotion." Given the tax benefits and the extra time off (UD has more religious holidays than all other human religions combined - sometimes several per day! Just choose which ones you want to observe.) associated with having a "religion" and the fact that no government agency is authorized to question your level of devotion, so long as your religion is happy with it - once a year good for you? That's fine with UD. Once a day more your speed? That's fine with UD, too. - What's not to like & be devoted to?
Of course, like all religions, Universal Divinity does have commandments... Or, rather, one "commandment" called The Prime Law... You ready for it? "You’re only here for a fairly short time. Have some fun, accomplish something, and try to be nice to each other."
That's it. And even that's subject to interpretation. There is also a formal suggestion - called the 'Key Guide': "Deception, Theft, and Unnecessary Harming of Others are to be avoided."
Not so bad, huh?