by Bill Anderson

You have the causality backwards. Males form tribes so that they can control a breeding population of women. Males who fail to do so will be conquered and their genes displaced, so violent conflict is unavoidable. These breeding populations will produce survival behaviors based on their genetic inclinations and their environment. These behaviors will be prioritized, or valued differently in each population, thus distinct value systems emerge (say monogamy vs polygamy for example). These distinct survival strategies are often incommensurate, and thus conflict is the result of their proximity. Some values are the result of “black swan events” which cannot be predicted or are multi generational processes which have catastrophic results. Pre-literate peoples communicated these lessons via myth, and sacralized (made static) those values as God given commandments.

So, religions don’t cause war, competing survival strategies cause war. Religion is the result of a value system (survival strategy), not the cause of it.