Richard Dawkins writes in his best-selling The God Delusion,

As Einstein said, ‘If people are good only because they fear punishment, and hope for reward, then we are a sorry lot indeed. ‘ Michael Shermer, In The Science of Good and Evil, calls it a debate stopper. If you agree that, in the absence of God, you would ‘commit robbery, rape, and murder’, you reveal yourself as an immoral person, ‘and we would be well advised to steer a wide course around you’. If, on the other hand, you admit that you would continue to be a good person even when not under divine surveillance, you have fatally undermined your claim that God is necessary for us to be good.