So far Lewis has been talking about the act of assuming the role of Christ, so that one day, we can achieve divine life. Indeed, Lewis claims that “assuming the role of Christ” sums up the entirety of Christianity.
Christianity consists of following the moral law and worshipping Christ—approximating a state of perfect virtue, so that, one day, one can achieve this state of perfection in Heaven.
Lewis summarizes how an ordinary person might progress from atheism to Christianity. Non-believers have their own desires and selfish interests; some of these people discover morality and a code of decent behavior. But when people merely accept a moral code, they continue to behave selfishly; they’re just doing the right thing in the hopes of achieving a reward later. The only way to graduate from mere moral obedience to true, selfless moral enlightenment is to worship Christ. And in the end, worshipping Christ inspires people to give up their selves; to surrender to Christ’s majesty and become united with God.
One of the most common misinterpretations of Christianity—or, arguably, religion—is that being a good Christian consists of simply obeying a set of rules and laws in order to get into Heaven (for example, there is a famous philosophical problem called “Pascal’s Wager,” which proposes that atheists might as well convert to Christianity, since the rewards of salvation are so enormous). Lewis’s point is that mere obedience, in the interest of achieving a reward, is not enough—one must accept that one’s obedience will always be insufficient, and that humanity is inherently flawed. When humans accept that they’re imperfect, they can truly worship Jesus Christ and give up their selves to him.
Giving up one’s self can be extremely difficult; indeed, humans instinctively want to protect their selves and remain selfish. And yet, in the end, the only way to be truly happy is to “hand over” ourselves. Atheists and non-believers are like lazy schoolchildren who think they don’t have to do the hard work of learning equations and memorizing dates. But when it’s time for an exam, the lazy schoolchildren realize how ignorant they are, and frantically try to “cram” for their exams. By the same token, a good Christian might get less short-term pleasure than a non-believer, but in the end, a Christian will be “prepared” for salvation in a way that an atheist literally cannot conceive of.
In essence, being a good Christian means giving up on one’s own selfish desires. Humans instinctively want to protect themselves and favor their own interests; therefore, becoming a Christian can be extremely difficult. And yet the long-term payoffs of worshipping Christ are undeniable—good Christians who humbly surrender their own desires will achieve salvation, while atheists and nonbelievers will be (presumably) damned.
In the end, the only purpose of Christianity is to make mankind one with Christ. The church has many projects—charity, education, etc.—but in the end, these projects are just means to the ultimate end of uniting man and the Son of God. When man and Christ unite, “the bad dream will be over; it will be morning.”
One implication of this passage is that all human problems are caused by the absence of a “oneness with Christ.” If humans could only surrender their self-interest and greedy desires, Lewis suggests, the world would be a much better place.