I have never been one to visit temples too often. The idea of a God that punishes was unacceptable to me even as a small child. And rituals & superstitions just aren't my cup of tea. Having said that, I do know of some practices having a scientific background, but are given a populist facade to make sure people follow them, and I certainly do follow them.
In a lot of situations, I seem to agree more with atheists than I do with believers. So what is God to me? For the most part, a source of inspiration that is the most pure and incorruptible. Being a student of science, every natural occurrence has a scientific explanation to me. So I don't think of God as some kind of puppet-master. Thankfully, my religious teachings do not prohibit me from believing that my ancestors were apes (figuratively speaking). So my faith does not blind me from simple truths like evolution. This trust in a supreme being lies totally in the spiritual domain of our existence. Like morality, it does not have a scientific/logical proof, nor does it need any.
So then, what is the 'use' of this belief? It inspires me to be a better person. Sure, we have idols among fellow humans for that. But sometimes you need something far different to inspire hope within yourself. Not everyone does, well I do. I admire the atheists who can inspire hope within themselves when there is none. And would most certainly like to read about them. Unfortunately, all great & famous stories of survival of the "rise from the ashes" kind that I have heard involve people who quote their belief in this supreme being as an inspiration to rise above. Not passing any sort of judgement here, I might have certainly missed some.
So there it is, my idea of God.....