There may be a certain modicum of decent behavior that we need to engage in in order to function socially. But sometimes people have a lot of money thrust into their hands, and so don't have to have the ordinary middle-class pressures. Or one can be very poor and desperate for money. If you are moderately privileged, you need morality to get along, but if you are really poor, you can't afford it, and if you are really rich, you don't need it.
Professional athletes and singing stars often find themselves with a lot of money, power, and acclaim that is beyond their maturity to deal with, and they often wreck their lives because of it. (Lindsay Lohan, Paris Hilton, Britney Spears, etc.) Kurt Warner seems to want to use his position for the benefit of others, but he is motivated, quite obviously, by religion.
To sum up, certain situations give us a reason to be moral, but those reasons don't hold up if the situation changes. A belief in moral theism, on the other hand, provides a moral motivation that transcends the situations in which we find ourselves.