I. The nature of sin
II. Man’s alienation from God
III. The meaning of grace
IV. The possibility of grace
V. The Fall and natural history
VI. In Adam all sinned: the spiritual unity of mankind
Although the doctrine is most central and most fully developed in Christianity, many theistic religions have some notion of a Fall and of original sin—the idea that people are sinful and the world is messed up because of some transgression by the first humans. To unbelievers, this idea sounds crazy. First, it seems unnecessary: we know perfectly well why people are bad already. Natural selection explains why humans feel hunger, sexual desire, and desire for status; it’s inevitable that some people will sometimes use illicit means to satisfy these natural cravings. So, for example, evolution explains lust, and lust explains adultery. What more is to be said? Second, it’s not clear how sins of one or two people could have such an influence on all the rest of us, even if we all are descendents of these two.
Such skepticism is only reinforced by the fact that Christians have generally done such a poor job explaining the doctrine. Often, those who take it upon themselves to explain original sin have ended up replacing the idea with some other one. For example, original sin is sometimes recast, not as an explanation of sin, but as simply the statement that people are sinful. For many, it has come to mean only a pessimistic attitude towards schemes for the perfection of man, or else it’s a general acknowledgment that one’s own motives (as well as others’) are tainted with selfishness. Sometimes, the doctrine is taken as a metaphor for the loss of childhood innocence or, for those of a more Hegelian disposition, for the alienating effects of the subject-object distinction. Let us, rather, be fully honest and consider the doctrine in full: the Fall refers to a purportedly actual, historical event that has had vast repercussions for all future generations. We shall see that there are good reasons for theists to believe that such an event actually took place.
What is it about human sinfulness that Christians think requires a supernatural explanation? Let’s return to the above example of an adulterer. His motivation is obviously sexual desire for a woman not his wife—what else is there to explain? First of all, a man is not just a machine that automatically responds to his strongest current drive. We are not mere slaves to our desires. If we were, we would be no more capable of sin than are animals, washing machines, or rocks. Each man is also self-consciously immersed in a world of value and disvalue, good and evil, duty and prescription. The adulterer has some idea that the wife he betrays and the mistress he exploits are not just raw material for his gratification. They are people, human beings, each one precious for her own sake, each one deserving to be treated as an end, not just a means. He also has some idea of the holiness of the conjugal bond and the viciousness of its desecration. He must have at least some sense of these truths, or else he would not be culpable for his evil. The sin does not consist in the desire that motivates it. The sex drive is, in itself, good and natural, and it has a necessary function. It’s not sinful to be attracted to a woman; what’s sinful is to ignore the fact that she is also a person entitled to respect and concern. What makes the sin is the negative act of ignoring objective values, of ignoring their claims on us. A man who felt a powerful desire for a woman but suppressed it out of devotion to his wife would not be sinning at all. In fact, we regard the refusal to give in to temptation as particularly meritorious, precisely because the positive act of recognition or love needed to persevere must be particularly strong, and this positive act is what we praise.