"Finally, on the theistic hypothesis God holds all persons morally accountable for their actions. Evil and wrong will be punished; righteousness will be vindicated. Good ultimately triumphs over evil, and we shall finally see that we do live in a moral universe after all. Despite the inequities of this life, in the end the scales of God’s justice will be balanced. Thus, the moral choices we make in this life are infused with an eternal significance. We can with consistency make moral choices which run contrary to our self-interest and even undertake acts of extreme self-sacrifice, knowing that such decisions are not empty and ultimately meaningless gestures."A friend of mine recently scolded her cat for starting to play with an electrical cord. It wouldn't do any good to lecture the cat about how dangerous electricity can be, so an imposed association between electrical cords and punishment are needed to keep her cat safe when no one is watching. The same applies to toddlers. Adult humans avoid chewing on electrical cords because they don't want to be shocked. No stand-in motivation needed!
— William Lane Craig, "Can We Be Good Without God?"
When it comes to moral situations, some philosophers try to show that acting morally is in our own best interest, either all the time or often enough that we tend to come out ahead in life if we cultivate moral habits. Other philosophers (and many preachers) claim that acting morally is in our own best interest because we will be punished or rewarded in an afterlife. The quote at the top of this post is such an example: William Lane Craig believes that self-sacrifice is "empty" if it doesn't eventually turn into huge rewards for the person doing the sacrificing.
In other words, there's a tendency to reduce morality to self-interest. I believe this is a mistake. While it's true that moral action often works in our own favor, the essence of morality is other-interest.
But there's a problem: some people don't have much in the way of other-interest. How do we convince them to act in the interests of others anyway? Impose an association between harming others and punishment, or an association between helping others and reward. It's another kind of stand-in motivation.
Punishment and reward are training wheels for human beings who can grow in understanding (to better achieve what they want and avoid what they don't) and who can grow in empathy (to better care about what others want). Training wheels might keep your bike from falling over, but you aren't truly riding until you no longer need them. When I read things like the quote at the top of this post, I see a desire for perfect training wheels: the appearance of moral justice without any need to act out of the interest of others.