EDITOR’S NOTE: In the last of three essays for Columbia, author and commentator Dinesh D’Souza examines the risks involved in not believing in God, refutes the arguments of popular atheists and offers a simple prayer for increasing one’s faith. D’Souza is the author of What’s So Great About Christianity (Regnery). His previous essays in this series were Why Miracles Are Possible (January 2008) and A Designer Universe (February 2008).

Skeptics say that we cannot know whether God exists, and in a sense they are right. In the Letter to the Hebrews, we read that faith is “the substance of things hoped for, the evidence of things not seen” (Heb 11:1). If the believer “knew,” there would be no question of faith. Consider this: I do not have faith that my daughter is in the seventh grade; I know she is in the seventh grade. Conversely, I do not know that heaven exists, but I have faith that it does. Faith is a statement of trust in what we do not know for sure.

Is such faith reasonable or is it “blind” as atheists frequently allege? This central human conundrum is the subject of what is famously known as “Pascal’s Wager.”

The concept of the “wager” is first found in The Alchemy of Happiness, a medieval work by Muslim theologian Abu Hamid al-Ghazzali. Blaise Pascal, a 17th-century French philosopher and mathematician who was familiar with the work of al-Ghazzali, later derived his classic argument. In giving the wager its current expression, Pascal places an unavoidable choice before believers and unbelievers alike.

Pascal argues in his Pensées (Thoughts) that we have to gamble in life. Let’s say you are offered a new job that may take your career to new heights. It looks extremely promising, but there are risks. There is no way in advance to know how things will turn out. Or you are in love with a woman. You have been dating for a while but cannot be certain what marriage to her is going to be like for the rest of your lives. You proceed on the basis of what you know, which, by the nature of the matter, is inadequate. Yet you have to make a decision. You cannot keep saying, “I will remain undecided until I know for sure.” If you wait too long, she will marry someone else, or you will both eventually die.

In the same way, Pascal argues we will never understand everything in advance when making our decision about God. No amount of rational investigation can produce definitive answers, since what comes after death remains unknown. Therefore, we have to examine the options and make our wager.

But what are the alternatives, and how should we weigh the odds? Pascal argues that we have two basic choices, and either way we must consider the risk of being wrong.

If we have faith in God and it turns out that God does not exist, we face a small downside risk: metaphysical error. But if we reject God during our lives, and it turns out he does exist, there is a much more serious risk: eternal separation from him. Based on these two possible outcomes, Pascal declares that it is much riskier to be an atheist. In the face of an uncertain outcome, no rational person would refuse to give up something that is finite if there is the possibility of gaining an infinite prize. In fact, under these conditions it is unreasonable not to believe. Pascal writes, “Let us weigh up the gain and loss involved in calling heads that God exists. If you win, you win everything. If you lose, you lose nothing. Do not hesitate, then: Wager that He does exist.”

The ingenuity of Pascal’s argument is that it emphasizes the practical necessity of us making a choice. This necessity is imposed by death. There comes a day when there will be no more tomorrows; we all have to cast our votes for or against the proposition on the ballot. The unavoidability of the decision exposes the foolishness of agnosticism and religious indifference. People cannot refuse to choose when there is no option to abstain. The refusal to choose becomes a choice — a choice against God.

Pascal also exposes the pose of the atheist who fancies himself as a brave and lonely man facing the abyss. We admire a man who is steadfast in the face of unavoidable adversity. If we know we were alone in the universe and that death is the end, there is no alternative but to stand tough in our mortal skins and curse the darkness.

But what would we think of a man who stands ready to face a horrible fate that he has had a chance to avert? If you are trapped in the den of a hungry lion and there is a door that may offer escape, what sane person would refuse to jump through that door? Viewed this way, the atheist’s position becomes a kind of reckless intransigence, a foolish attempt to gamble with one’s soul.

Atheists sometimes express their bafflement over why God would not make his presence more obvious. The popular American astronomer Carl Sagan once suggested that in order to dispel all doubts about his existence, “God could have engraved the Ten Commandments on the moon.” Pascal supplies a plausible reason for what he calls the hiddenness of God. Perhaps, he writes, God wants to hide himself from those who have no desire to encounter him, while revealing himself to those whose hearts are open. If God were to declare himself beyond our ability to reject him, then we would be forced to believe. Pascal says that perhaps God wants to be known not by everyone but only by the creatures who seek him.

Leading atheists are aware of the power of Pascal’s wager. Best-selling author Christopher Hitchens (God Is Not Great: How Religion Poisons Everything() can do no better than to launch a personal attack on Pascal as a “hypocrite” and a “fraud.” Richard Dawkins ((The God Delusion() proclaims Pascal’s argument “distinctly odd.” And why? Because “believing is not something you can decide to do as a matter of policy. At least, it is not something I can decide to do as an act of will.” Dawkins is right about this, of course, but the real issue is whether he wants to believe and whether he is open to the call to have faith.

Pascal writes that there are two kinds of reasonable people in the world: “Those who serve God with all their heart because they know him, and those who seek him with all their heart because they do not know him.” Pascal recognizes that faith is a gift. We can only ask God to give it to us. In the meantime, the best thing to do is to live a good and moral life, and to live as if God does indeed exist.

And pray the prayer of the skeptic, such as this one written by the philosopher Peter Kreeft: “God, I don’t know whether you even exist. I think you may be only a myth. But I’m not certain…. So if you do exist, you must be hearing me now. So I hereby declare myself a seeker, a seeker of the truth, whatever and wherever it is. I want to know the truth and live the truth. If you are the truth, please help me.” The Bible promises that all who seek God in this way with earnest and open hearts will find him.

Dinesh D’Souza is the author of many books, including What’s So Great About Christianity (Regnery). View his Web site.