In a sense, one can argue that self-interest is implicitly affirmed in Christian ethics. Really? Humm… Not so fast!

​On several occasions, the Bible commands us not to place our personal values and self-interest above God’s, and Paul urges us to consider the interests of others first. Heschel affirms that the essence and greatness of man do not lie in his ability to satisfy his ego, but rather in his capacity to stand above it, to set aside his own needs, and to sacrifice his own interests for the sake of others. That seems to confirm Jesus two greatest commandments:

You shall love the Lord your God with all your heart, and with all your soul, and with all your mind; You shall love your neighbor as yourself. Paul makes it very clear that “Let each of you look not only to his own interests, but also to the interests of others. (Philippians 2:4)

Apparently, there does not seem to be a morally legitimate role for self-interest in Christian ethics except for what Paul mentioned here. But notice that Paul’s words own interest appeal to the notion of self-interest. However, unlike what ethical egoism teaches, self-interest in the Scriptures is different. And there are two reasons for that.

First, there is a distinction between self-interest as a by-product of an act (Biblical view) and self-interest as the sole intent of an act (Ayn Rand’s ethical egoism, for example). God’s commands to the believer are not given solely for the interest of the believer but because they are parts of God’s moral commands per se. Second, Scriptures teach self-interest not as an end in itself but as a reason for doing some duty. It is a kind of exercising self-interest as a prudential, but not a moral, reason for doing something. And so, self-interest in the context of Scripture is not an intent for an action or motive or not as a moral reason, but only as a byproduct of an act.

By contrast, ethical egoism, for instance, the value of the results of our actions must be solely a function of the fact that they benefit the agent herself. And so, an act is moral if and only if it maximizes my own self-interest. Unlike the biblical view, ethical egoism in that sense claims that self-interest is both necessary and sufficient for something to be my duty.

Put simply, the nature of self-interest in Scripture differs from that in ethical egoism. As C.S. Lewis argues, there are some rewards that are proper. These are the things that naturally connect with what we do. If, by being an assistant college professor, I happen to become a millionaire, this money is not a natural reward because it is not tied to the activity for which the reward is given. Meanwhile, if I am a real estate investor and I become a millionaire, this money is certainly not foreign to the desires that ought to accompany my real estate career.