A lot of people, Lewis says, believe that God is “the sort of person who is always snooping around to see if anyone is enjoying himself and then trying to stop it.” Furthermore, many people believe that morality itself is a way to limit happiness. But the truth is that morality is a set of rules for running the “human machine”—sins, Lewis argues, might seem to be fun in the short-term, but they also distract us from salvation and thus from long-term happiness.
In Book Three of Mere Christianity, Lewis will study the rules of Christian morality in more detail. He wants to fight the stereotype that Christianity is concerned with limiting human happiness; in order to do so, he’ll try to show that Christianity actually leads to the ultimate form of happiness—salvation.
Some people prefer to say that they believe in “moral ideals,” rather than moral law. The problem with such a mindset is that it makes morality sound like an arbitrary, personal taste. The notion of moral idealism may also be dangerous because it suggests that overall “ideals” are more important than adhering to morality at every step of the way. By discussing moral law, we remind ourselves to obey the rules at all times.
Before he gets into the details of Christian moral law, Lewis emphasizes that it’s important to have moral laws, as opposed to vague ideals, because morality is a constant struggle to do the right thing—and hazy things like ideals rarely speak to specific situations and the difficult choices of daily life.
There are three ways that the “human machine” goes wrong. First, humans drift apart; second, an individual human being’s desires interfere with morality; third, humans forget about salvation. To make an analogy: morality resembles a fleet of ships. The voyage will fail if the ships drift apart, if there is a mutiny on one ship, or if the ships forget their destination. Thus, morality is concerned with three things: 1) harmony between individuals; 2) the inner harmony of the individual; 3) the general purpose of life (salvation). In modern times, people focus too exclusively on the first component of morality, ignoring the latter two. Politicians think that “morality” means everyone getting along together. While the harmony of the group is important, people cannot be called virtuous unless individuals behave morally and aspire to salvation.
Morality is both internal and external: it’s concerned with an individual’s piety and righteousness, but it’s also concerned with how different people get along with one another. Furthermore, Christian morality is concerned with the overall direction of a person’s life—namely, salvation in Heaven. The implicit message of this passage, which Lewis will make explicit later on, is that it’s possible to be immoral by concentrating too exclusively on only one or two facets of morality and neglecting the others. Morality, then, is a constant balance between individual, society, and salvation.
For the rest of the book, Lewis is going to “assume the Christian point of view, and look at the whole picture as it will be if Christianity is true.”
By this point in the book, it’s pretty clear that Lewis is explicitly advocating for a Christian worldview and a Christian God—he’s no longer speaking of an “all-powerful, abstract being.” Notice that Lewis never offers any logical proof (other than, arguably, the “trilemma” of Christ) that Christianity is the “right” religion and others are wrong; he mostly just makes a jump from one subject to another.