Spiritually Oriented

I have been thinking more about the strong move toward religion in the former Soviet Union after 70 years of communist regime and their strict following of scientific atheism (see yesterday's blog). Is the belief in God or gods universal among cultures? I haven't been able to find verification and I am not an expert in the field but I think that every single culture that exists in the world has a belief in a God or gods. From the deepest jungle to the most isolated group in the Arctic, each society follows some sort of religion. Why would this be? Why didn't some groups come up with other possibilities. Why didn't some decide that something like evolution or aliens were responsible for the existence of life? The tenants of these two possible explanations do not seem any more far fetched than the existence of a Supreme Being. Wouldn't it seem logical that some group take one of the other possible explanations? The explanation that comes to mind is that within humans is a spiritual part that looks for God. There are many questions I have about the "God" explanation but the ubiquitous belief system seems to be a point in its favour.