The spread of the two most successful faiths, first Christianity and then Islam, is partly thanks to a tweak in their theology: unlike pagan and animist traditions, with their teeming pantheons of gods, they were monotheistic. Their god wasn’t a god, he was God. The One and Only. His moral rules were universal, applicable to all. Accepting the truth of other gods and breaking His rules was now a heresy, a significant rejection of the monotheist’s criteria for claiming status. This incentivised believers to convert those around them and conquer their neural territory.
