I propose a definition where god is the most basic learned survival mechanism: be good to yourself and the world will be good too (this all takes place inside your head, call it "Heaven"). This includes influencing surroundings to be supportive (without harming anyone), because the coherency of a persons action comes from their previously conceived plan of what they hope to accomplish. By learning from our parents we assume this is the natural state of affairs for the world. But outside that expectation, that is, the "Real World" (call it Earth), is chaos and conflict. EXCEPT possibly where we communicate with other people and creatures and acknowledge their own survival mechanism that operates the same way. Integrating with god in others makes him/her universal. I know this is going to sound vaguely familiar, but god lives (exists) in heaven and cares for you, without god you really won't survive.
This is a survival mechanism because we tend to die without it. People, especially kids, old, and powerless (unimportant) people die without love (a positive self image) or they become rationalistic psychopaths, but both live in make-believe to be happy enough to survive. Creatures without ego become food, but expressing ego can be problematic. Expressing ego will explain the extreme permissions religions allow their gods so that anything is acceptable if it justifies existence so that any critique is only a hindrance to megalomania. If God's jealous and selfish, it's because he's paranoid that his intellectual creations may turn against him and they often do because his chosen, like god, are also insane having been created in each others image (present company excepted of course).
Now I'll divide this god into good & evil:
the evil part is the same god (aka survival mechanism) seen in other creatures watching out for themselves. I kinda suspect the "God the father" of the Christian holy trinity and the infamous "jealous god" is that same aspect because we have to be obsequious to them to survive, but that might be a result of my own experience. Maybe not, lets see; there are people who are raised predominantly by one parent or the other, it's usually cultural. Most kids depend on their mothers for the first few years of their life so that's where they learn self kindness. Western and Abrahamic religions definitely do. Most male groups are oriented around some kind of competitive or profit making enterprise. That is, a unified defense against that aspect of god. Bad stuff like war, hell, & hungry tigers are just a ceremonial representation of the evil or non-survival mechanism that aggression from others presents. Another way to say it is if you want a paying job, you have to talk to the man, & "none may come to the father but by me" (the good aspect). Or: don't insult/attack/kill your employer (or whoever it is), he's just a guy like you & has to deal w/ the same crap & chaos that you do.
OK I'm running this into the ground because I wanted to give it a little enlargement, but it's just gumbo. the meat is in the first paragraph. Um... but wait, first something important:
The importance of importance is important because it's how a people survive in a group and, as a member of that group, assure that the group will defend them as individuals from trivialization and a slippery slope to contempt, desperation, banishment, and death from exposure. It could still be gumbo but if it's plausible to enough people, then it's important (this blog for example*). An individual with group security is better off than say living in a dumpster (people in dumpsters usually are not too important), whereas the pope (who has a special hat) & Dick Cheney (who has a special sneer) are way important. They positioned themselves so that their influence also secures their personal livelihood. See, you have to convince people that you represent something important, having them by the nuts helps too, as does threatening Imminent Domain in exchange for a donation. Check here if you believe gumbo is important. Better yet, write a long paragraph in the comments. The twist comes when considering that everything we say and do is to make someone take us seriously. Gumbo is ok but unremarkable. It'll keep us alive till The Aliens land, but then we'll need a better line if we want to compete.
* Most of the people who follow this blog are FBI shrinks.