Holy cow! I think someone skipped their Philosophy 101 class.
Of course you can derive a moral basis for behavior without a belief in a divine being.
But what about people of no faith at all?
The issue is faith. You can debate whether or not atheism is a religion, but it's evident that atheists do have faith. You can't prove a negative, so the greater burden of proof is on the atheist to convince him/herself that there is no God, god, or gods. That in itself requires faith. My faith as a Christian is in Jesus Christ, the Son of God. Their faith as an atheist is in the fact that all proclaimed or unproclaimed deities do not exist. If they could prove that, THEY would be God!