God is an effect of abstract thought, not a cause

Believers often ask what it is that makes us human. In anthropological terms, we are the only species that makes tools to make other tools. In terms of our psychology, we seem (so far) to be the only species capable of abstract thought. This would include, but not be limited to, art, philosophy, literature, ritual, superstition and religion. Believers often like to point to these things as though the god concept is the cause of this abstract thought but there is a strong case to be made that "god" is a result of this abstract thought. It is a culmination of hundreds of thousands of years of psychological evolution. We're not the only hominid species to have had these concepts even though ours have clearly developed to become quite advanced. Here are some articles to show Homo Neanderthalensis and other hominid species demonstrating abstract thought (clickable links)

Neanderthal Art and symbolism
Neanderthal deliberately buried their dead
A Neanderthal ritual burial at Shanidar? - There is some question over this, but a burial seems to have been buried with flowers. Destractors say that the flowers were introduced by the digging of animals but the supporters say the concentrations are too high to be animal intrusion
Ritual handaxes of Homo Heidelbergensis? - Perfectly usable hand axes that were never used but seemingly placed in a ritual context.

I will add more as I come across them.