Many of the people who claim to believe in God say that they find it hard to believe in a personal God, with thoughts, ideas, and plans. Christians agree that it is impossible to understand, fully, what God is like—however, Christians do offer some idea of what God must be like.
Characteristically, Lewis begins this chapter with a modest admission that his theories about God are just that—theories. He will, however, still attempt to make some hypotheses about what God is like.
Christian theology teaches that when humans die and go to Heaven, they become part of God, and yet also remain separate from him, retaining their thoughts, memories, and personalities—a difficult concept. To understand this idea better, Lewis asks us to consider the three dimensions of space. A two-dimensional shape is composed of many one-dimensional lines, just as a three-dimensional object is made of countless two-dimensional surfaces. It could be said that in Heaven, souls become a “part” of God and yet retain their essence in the same way that a square is a “part” of a die—the square is still recognizably a square, but it’s also part of a greater thing. Following this logic, God exists as three separate “persons,” yet is also one overarching being, in the same sense that a die consists of six squares, and yet is one three-dimensional shape.
The final Book of Mere Christianity (like the more mystical aspects of religion itself) is full of paradoxes and contradictions. Here, for example, Lewis theorizes about how souls in Heaven are both one with God and separate from him. Lewis’s analogy for such a concept is that souls in Heaven are connected to God in the same way that squares are connected to a six-sided die. As with many of the other analogies in the book, Lewis presents his comparison as a rough approximation of a highly complicated truth—an image only, and not something to cling to or over-analyze.
It is very difficult to speculate about the nature of God, since God is unfathomably complex and majestic. But there are ways for people to begin to understand God. For instance, on Earth, humans can communicate with God through prayer. In the act of reaching out to God, human beings transcend earthly life (which Lewis calls bios) and experience the higher, spiritual life (which Lewis calls zoe). The intellectual discipline of theology arose from humans’ limited experiences of zoe during the act of prayer. Indeed, one could even argue that theology is an experimental science, in which humans use an “instrument”—their whole selves—to study God and zoe.
Lewis sums up what he’s been alluding to so far: there are two forms of life, one base and earthly, the other pure and spiritual. Mortal life is defined by the first kind of life, bios, while the afterlife (assuming one’s soul goes to Heaven) is defined by the second, zoe. However, it’s possible to experience fleeting moments of the second kind of life in the act of prayer. One could certainly disagree with Lewis for characterizing theology and prayer as forms of “science”—science, after all, is concerned with the testing of hypotheses, whereas prayer and faith stem from the certainty of Christ’s existence.
Every few years, Lewis says, someone peddles out a new, simplified religion that tries to compete with Christianity. People who sell such religions are wasting their time, however—Christianity is the only religion that’s as complicated as life itself. False religions are appealing because they’re simple, but in the end, Christianity, with its difficult distinctions—like those described in this chapter—is more valuable.
It can be frustrating that Christianity offers mortal humans nothing more satisfying than momentary snatches of zoe. But the fact that spiritual salvation is so difficult to achieve is a part of the challenge and the struggle of Christianity. It is, of course, difficult to achieve zoe, but this makes zoe all the more valuable and satisfying.