Hope is another one of the Theological virtues: Lewis defines it as the ability to continually “look forward to the eternal world.” Hope gets a “bad rap” these days—people associate hope with naiveté and escapism. In fact, the Christians who look forward to Heaven most fervently are often the same people who celebrate life on Earth with the greatest enthusiasm, and do the most to improve it.
One of the most persistent criticisms of Christianity is that it’s overly concerned with Heaven, to the point where it encourages its adherents to neglect their time on Earth. (Or, Karl Marx wrote, “religion is the opiate of the masses.”) Lewis’s reply is that good Christians care deeply about their lives on Earth.
It is difficult for most people to “want” Heaven—our desires are too focused on material, earthly things. However, our desires for earthly things—marriages, vacations, jobs, etc.—usually fade away over time. There are three distinct ways of responding to such a phenomenon, Lewis says. First, people foolishly assume that earthly desires need to be replaced with other earthly desires. For example, a person who goes on a vacation and has a bad time will delude herself into thinking that she’ll just have to go on a more expensive vacation next summer. Second, people conclude that there is something inherently unsatisfying about life itself, and that people should learn not to expect too much from it. Third, and best of all, people conclude that earthly things are never entirely satisfying, but spiritual things are.
As Lewis approaches the fourth and final part of his book, he begins to focus on the difference between life on Earth and life in Heaven. The fundamental thing about life on Earth—or at least ordinary, day-to-day life, as Lewis sees it—is that it’s concerned with material things, both for survival and for pleasure. The problem, then, with earthly, material life is that its pleasures are transient—material things, whatever their nature, will gradually become less exciting or fulfilling. Religion allows people to find a new, higher form of happiness—the worship of Jesus Christ.
Some people smugly say that Heaven sounds boring—who wants to sit on a cloud and play a harp forever? Lewis responds by saying that the traditional imagery of Heaven (clouds, white robes, harps, etc.) is just that—imagery; a way of expressing the expressible. One might as well say that when Christ instructed his followers to be like doves, he wanted us to lay eggs.
Lewis acknowledges that he doesn’t know what Heaven is like—but he strongly criticizes people who take the traditional description of Heaven literally. Christianity is full of heavily symbolic language—and for atheists to take such language literally is to make a straw man argument.