I suddenly got a little curious what stance D&DG takes toward worship of deities and what benefit the gods get from being worshipped. In Planescape and Forgotten Realms, it seems that gods need to be worshipped or they die. Other settings have their gods more or less independent of worship - the impression I've gotten from Greyhawk indicates that those gods don't need worshippers at all (two of the handful of Greater GH gods, Istus and Boccob, seem to have rather few worshippers), and in Mystara the Immortals get some amount of power from worshippers but it's not their sole power source.

So, what does D&DG have to say about deities needing/having use for faithful?