[_urga]

"We can have a concept of moral and good without belief in a god"

Sure, but how would that be an objective, universal, absolute standard of good and evil? You claim philosophy, and yet this is an age-old philosophical problem. For example, see Hume's guillotine, i.e. Hume's is-ought distinction.

"teaching people to be nice to each other lies in everyone's interests, a God serves no purpose here."

Is truth determined by fact and reason, or merely by the purpose it serves?