We Witches are pretty lucky - instead of having only a male God, we have both a God and Goddess - two halves of our take on the Supreme Being, whom we call Spirit. Our God and Goddess are absolutely, completely equal - neither is more powerful or more important than the other. Some Witches worship the Goddess with more enthusiasm than they do the God for various reasons - a common one is that the Witch feels that, because the Goddess has been ignored for so long by so many, She deserves a little extra passion. I personally put the same amount of energy into worship for the God and the Goddess - I don't favour one over the other. I would say I relate better to the Goddess, being a woman, but I don't favour the Goddess over the God.
Humans tend to want to believe in something higher than ourselves, but it hasn't always been that way. Early humans first started burying their dead in a ritual fashion, with flowers and grave goods (instead of just leaving them laying around for the animals to eat), about 300 000 years ago when the most evolved humans were Homo neanderthalensis - Neanderthals. This probably had a lot to do with the evolution of larger brains, allowing us to think about things beyond basic survival - humans around this time were also starting to do things like agriculture, making stone tools and migrating beyond Africa, and this spirituality was probably just another cultural development. You can see why scientific types don't tend to be really religious - spirituality and belief in things beyond this world began with Neanderthals. We've just never given it up since, and it's evolved into things like Christianity - and it all began with a species that is sometimes described as being closer to the apes than to modern humans.
As for the God and Goddess... well, it's nice to think of them sitting up there like the ancient Greek gods on Mt. Olympus, but as they're supposed to be immanent, I think of them as being like the Force (as in Star Wars) - in and around everything as kind of an energy field, connecting everything.