How do you respond to the egoist challenge that man do reason to be good?

We do benefit in our own heart by being good. If we don't we are just putting on a false bravado. I was always told by my Dad to beware of the person who has to tell you how good he or she is. To be good is to treat others the same way we would want them to treat us. You catch more flies with honey than you do with vinegar.