What defines and shifts in-group/out-group boundaries? Do religious beliefs and practices affect the expansion of the social circle beyond kin and kith? What are the effects of religious reminders on moral behaviour? The relationship between religion and morality has been a focus of much of recent cognitive and evolutionary research. I will start with addressing the theoretical foundations that place religion within the context of evolution of cooperation and use empirical cross-cultural study of moral prejudice against ateists as a showcase of the strong morality-religion connection. In the main part of my presentation, I will introduce LEVYNA reseach investigating the various mechanisms religious systems use to regulate human social behaviour, reporting mainly on effects of beliefs in moralistic punitive gods and of religious music on dishonest behaviour.