When discussing Jesus Christ and his teachings, we have to face a basic fact: Christ came to Earth to “suffer and be killed.” When Lewis was an atheist, he thought that Christians had the same theory about why, exactly, Christ sacrificed himself: after the fall of man, Christ volunteered himself to “absorb” the punishment of man—thus, Christ died for mankind’s sins. Now that he’s a Christian, though, Lewis realizes the truth: the important feature of Christianity is not why, exactly, Christ died for our sins, but rather the fact that mankind has a “fresh start” thanks to Jesus Christ. Theories about the circumstances of Christ’s sacrifice may be important, but it’s not necessary to believe in any one of them to be a Christian.
In this chapter, Lewis turns to the central truth of Christianity: Jesus Christ died so that human beings could achieve salvation in Heaven. Interestingly, though, Lewis doesn’t offer a specific answer to the question of how, precisely, Christ sacrificed himself for mankind’s sins. In declining to do so, Lewis refuses to support any specific Christian sects (many of which have different interpretations of Christ’s sacrifice), and instead emphasizes the common kinship of all Christians.
Lewis now talks about the relationship between theory and reality. In science textbooks, we’re often given a metaphor that’s said to “explain” a complicated phenomenon, such as atomic motion. But metaphors aren’t exactly the truth: they’re just guidelines. The truth about atoms—or, for that matter, Jesus Christ—cannot be pictured or totally understood; humans can just try to approximate the truth.
Lewis emphasizes that his book shouldn’t be interpreted as the “be-all, end-all” explanation of Christ, God, and the universe. There are many concepts, he argues, that are beyond human comprehension. Thus, Lewis will sometimes offer convenient stories and analogies that help Christians wrap their minds around the complexities of their religion.
Even though it’s not necessary to believe in any single theory for why Christ sacrificed himself, it’s worth looking at some of these theories more closely. Lewis has already gone over the theory that Christ volunteered to bear mankind’s punishment for sinning in the Garden of Eden. But this seems to be a “very silly theory,” since it suggests that Christ “convinced” God to let mankind off easy. Furthermore, the theory implies that, had Christ not sacrificed himself, innocent human beings would have gone on being punished for the sins of their ancient ancestors, Adam and Eve—an idea that seems almost barbaric.
Lewis entertains the theory that Christ sacrificed his life to redeem the sins that mankind accrued because of Adam and Eve’s sinful behavior in the Garden of Eden. He admits that, on the surface of things, the idea that human beings should be punished for their ancestors’ sins seems deeply immoral.
Lewis now backs up to try to understand how it’s morally sensible for people to be punished for Adam and Eve’s sins. Lewis compares mankind’s “burden” to a financial debt—when somebody has lost a lot of money, he'll lean on his friends to help him pay off the debt. Similarly, Adam and Eve got mankind “into a hole”—by trying to be greater than God, they sinned greatly, dooming their descendants to a life of pain.
One could certainly disagree with Lewis here—it seems like a basic tenet of moral law that humans shouldn’t be punished for crimes they didn’t commit. But this is another instance where Lewis takes a more aesthetic view of Christian doctrine and human history, and doesn’t really have a logical argument to defend it.
In order to escape the life of pain with which God punished the human species, humans must repent their sins. But repentance is difficult—the people who need to repent most urgently (i.e., really evil people) are least likely to do it. However, God helps humans repent by giving them the gifts of reason and love. The problem with repenting is that God, as an all-powerful being, cannot really teach humans to repent, because God himself never needs to repent; the entire concept of repentance is foreign to him. Therefore, God sent a material version of himself to Earth—Jesus Christ—in order to teach humanity how to repent sin. Christ repented in order to set an example for future generations of human beings.
Lewis speculates that part of why God sent Jesus Christ to Earth was to teach human beings how to repent their inherent sinfulness—a task that God, as a perfectly moral (and spiritual) being, was not equipped to perform himself. Jesus Christ, a man, was able to connect to human beings on their level and instruct them on how to repent and achieve salvation.
It might be objected that Christ’s repentance was “easy,” because he was divine. It’s certainly true that it must have been easier for Christ to repent because he was a virtuous man with a divine nature. But why should this mean that we shouldn’t be impressed with Christ’s sacrifice? One might as well say that children shouldn’t respect a teacher who shows them how to write, because “it’s easy for grown-ups”—easy or not, the teacher passes on an important lesson. Lewis has just given a “picture” of Christ’s sacrifice. But of course, his picture is just another theory—“if it does not help you, drop it.”
Christ’s sacrifice may have been “easier” (though not easy) than it would be for an ordinary man—but this doesn’t mean that it shouldn’t be impressive or crucial for humanity. Lewis closes by reiterating one of his main points from the chapter—sometimes, his ideas are just theories, designed to help humanity understand God’s mysteries. One can be a good Christian without agreeing with Lewis.