There are things we don't yet understand about the Universe and some of those things can appear to be dark, scary, dangerous and mysterious. Religion exploits this feeling of vulnerability that we have by proposing a deity who will shield us from the menace of the mysterious. It's a deity, though, who must be both comforting and menacing at the same time. He will protect us and, eventually, provide us with an eternal home away from all insecurity. It's a very alluring prospect. You don't need to have believer genes to be taken in by that, any more than I need money-lust genes to be excited by winning the lottery. But you mustn't reject him, as he then becomes far fiercer, more menacing and vengeful than those dark mysteries could ever manage.