I have been trying to do that for years now, and it's tricky because the concept so expansive that any box you put it in doesn't seem big enough. I'll try to be concise instead of confusing, but we'll see. I just think a full answer is automatic TLDR. Here's my best effort:
Let 's' stand for self, to include all psychological and biological aspects of personal existence, and compound them 'h' humanity, which describes the collective efforts of 's.' This is further compounded by 'u' for universe, to include all natural laws and manifestations regarding energy and matter. Add to this 'n,' any natural number to describe all that is not known that can be known, from tomorrow's weather to the next major scientific breakthrough.
All these concepts filter through our mind to conceive of an entity that is at once the perfection of ourselves, our species, and our world. This conception is all we can know of God. Regardless of whether or not a divine intelligence actually exists, our understanding of it is subject to this process. The formula is neutral in regards to right and wrong, but I find that when break any belief system down into the formula, there is a definite tendency towards harmony, which necessarily qualifies some actions as optimal and others as taboo.
There is a claim that we are born atheists. I believe that couldn't be more wrong. I submit that having a concept of God is an inherent part of being human. To deny God is more of a semantic exercise, a mere distancing the concept from objectionable qualities it inherited from cultural tradition. The god of an atheist is one without any anthropomorphic qualities or revelatory authority, but in function and purpose is identical to that of a believer. They all strive for a state of perfection in love and harmony, and will do whatever they believe best to accomplish its goals. They are all followers of God.