Why Religion?

I was listening to my CDs of Will and Ariel Durant's book, The Lessons of History. One thing that Will Durant said was that he felt religion, and particularly Christianity, was necessary to people because religion is a stronger support of moral codes than anything else, and that when religion is abandoned, so are morals. Dr. Durant is something of an agnostic. He says he believes in God if God is defined simply as a creative force.

My question for you, dear readers, is, "Do you think he's right?" Or do you think religion is no more necessary to maintain morality (and you can toss ethics into the mix, as well) than law or tradition or education or anything else?

Discuss.