Kant believes that humans have a tendency engage in evil behavior, and that this is undeniably our own fault. He argues that when we make decisions, we often put our inclinations first, combine them with our sense of duty, or ignore duty altogether. In his eyes, each of these tendencies qualifies human beings as morally evil.
Kant does propose a solution to the problem of evil. He finds the solution in a reinterpretation of Christianity. Specifically, he believes the solution lies in a reinterpretation of the role of Jesus Christ, and humanity's proper relationship to Jesus. Kant says that the idea of Jesus Christ, stripped of particular religious beliefs surrounding him, is simply the idea of a perfect moral being. The features of Jesus, the perfect moral being, jibe with people's conception of a morally perfect individual. We naturally think of morally perfect individuals as those people tempted by, but resisting of, various illicit desires. We think of them as exercisers of conscientious willpower. We do not think of morally perfect people simply as people who consistently avoid evil or are incapable of performing evil. A morally perfect being must be capable of falling from grace but able to resist the fall. According to Kant, we can wash out evil by modeling ourselves on this perfect moral being.
Guilt will likely ensue when we see the gap between the perfect moral person and ourselves, but Kant says that our past moral blemishes are erased when we take Jesus as our model, because we have wholeheartedly committed ourselves to a new way of life. If we are truly committed to becoming better people through constant obedience to the moral law, then we should feel morally upright. Kant argues that so long as we do not mistake our wholehearted commitment to the moral law as a guarantee of future good behavior, we can be reasonably confident that our behavior will continue to be virtuous. This is especially true if we can see the concrete effects of our conversion to the moral law. We can be confident that we will continue to remain virtuous people by doing good deeds consistently.
Some philosophers have claimed that Kant is offering a slightly modified version of Christianity by urging people to model themselves on an ideal being. These philosophers point out several intersections between Christianity and Kant's moral religion: strong feelings of guilt, worries about atoning for past transgressions, and concerns about how to retain a pure heart in the future. This criticism argues that Kant's moral religion does not have anything distinctive to offer, while sharing some of Christianity's drawbacks. Kant's moral vision does differ from Christianity in important ways, however. First, the notion of original sin does not appear in Kant's philosophy. (Original sin states that since Adam and Eve sinned in Eden, all humans are born sinful.) In Kant's view, we know human beings to be naturally evil because our experience tells us they are, not because we know a distant ancestor ate something forbidden. Kant also believes that we have a natural predisposition to good conduct along with our tendency to do evil. Still, Kant does agree with Christian doctrine in emphasizing the importance of cultivating a pure heart and a wholehearted respect for the moral law.
Critics of Kant also charge that a commitment to the mere idea of a perfect moral being is not enough to motivate moral conduct. Devoutly religious people might say that it is not enough to believe in the idea of Jesus. God had to send his son to Earth because humans need another human to emulate, not merely the idea of a perfect human.