I agree with those reasons but I would add to it; there is an innate spirituality that most people have. You feel it most often when you are face-to-face with the wonders of the natural world. Hiking in the mountains etc. Meditation can bring this about too. I feel like this is a uniquely human quality that comes when we are overwhelmed with awe for our natural world and the human condition. People feel the need to ascribe this to God, some people may call this feeling God. I have no problem with that. I have a major problem with the forming of a religion that is solely of human construct based around those things: explaining the natural world, the moral code and spirituality. Also, fear of death is certainly a reason people create religion/god. There are plenty of reasons people create God/religion.
Loneliness is probably an inevitable consequence of understanding. If you see what other people don't, it sets you apart. On the downside, it's common consequence of serious mental illness too. Buck up though -- I'm betting you're an instance of the former rather than the latter...