FWIW, I should have said higher purpose. From what I have observed, most good people subordinate themselves to a higher purpose. That can be all kinds of things. Belief in doing the right thing, God, your children, etc.
Tying a higher purpose to doing good is meaningless if you're just saying that good people believe in doing the right thing. I believe in doing the right thing, but I wouldn't say my existence is subordinate to that. It also doesn't make sense as a reply to someone saying that "you can walk the straight and narrow path without the carrot of eternal salvation or the stick of eternal damnation."
