The amygdala is a part of the brain with many roles, and including a role in the development of empathetic or "moral" behavior.
How can you be good without God? How can you be good with the Christian god? How can parents believe in a "loving" Father could doom his kids to an eternal lake of fire, or wipe them all out in a global flood, or kills his only good kid then lets the brats off the hook? How can they raise loving, moral children? To the extent that they do, it's due to behaving like all the other social animals rather than bringing up kids to fear God.
This TED talk covers the neural basis of morality and proposes ways to change the brain. (Won't work for murderers, though)