InterVarsity Press

How Can I Know That What I Believe Is True?

By James W. Sire

There are many important questions of life. Some of these go to the root of our understanding of reality. One such question: Is there a God? If there is, what is this God like? How can we tell the difference between right and wrong?

Here, then, is the problem: How can we test the truth of the answers we hear to such questions?

There are three major tests for truth: (1) consistency, (2) coherence and (3) completeness. All of them can be summed up in one principle: When it comes to the major questions of life, the answers most likely to be true are those that give the best explanation of what we wish to have explained. If an answer or explanation does not contradict itself, if it coheres with what we otherwise believe to be true, and if it accounts for all the available evidence and alleged counter-evidence, then it is probably true. If it passes these three tests better than the alternatives, then it is most likely to be true.

What, for instance, explains how we can tell the difference between right and wrong? Two possible answers are naturalism (another name for atheism) and Christianity.

Naturalism proclaims in Carl Sagan's quick definition that "the cosmos is all there is, ever was and ever will be." That means that there is no God, just matter and energy in ever-shifting combinations. It means, in other words, that all there is just is. There is no final meaning in the world, just those meanings we give things, events, ourselves and others. Our sense of morality—good and evil, right and wrong—is just a fact about us. Since there are many different senses of right and wrong and these senses often conflict, none of them can be the judge of any other. Some of us are pro-choice concerning abortion, others pro-life. Each side insists that its view is right. The pro-choice side says that it is the absolute right of each pregnant woman to decide whether to carry the fetus to term. The pro-life side says that the unborn child has an absolute right to be carried to term by the mother.

But from the standpoint of naturalism, these two views are just facts about us. There is no way to determine which view should prevail in society. Neither can be shown to be right or wrong. But note: It is not just that we can't tell which is right and which is wrong, it is that such a distinction transcending human opinion cannot exist. One cannot get "ought" from "is," and that's what naturalism requires us to do. In short, naturalism fails to give a foundation for one of the deepest issues of human life—the issue of life and death itself. If naturalism is true, there can be no justice on the basis of an objective standard that measures all human beings. There can only be the adjudication of power: physical power, rhetorical power, political power, social power (i.e., the power of tradition) or charismatic power (i.e., the persuasive power of personality).

Christianity is very different from naturalism. Christianity says that the cosmos is not the only thing that exists. Only God always is, ever was and ever will be. And this God is infinite, personal, good and intelligent. He created the cosmos to be as he wanted it to be and created us as human beings in his own image. Each person, from the unborn to the aged, is therefore valuable. All people have a right to life.

The foundation for the difference between right and wrong is, therefore, not in the changing and often contradictory opinions of God's human creatures (us) but in the character of God himself. This biblical conception of reality explains (1) the reason why we humans make distinctions between right and wrong (God has built into us this capacity when he made us "like" himself) and (2) the reason why some of our opinions about right and wrong are correct (we are right when our views reflect those of God).

In short, Christianity gives a better explanation for the fact and nature of our moral judgments than does naturalism and is, on this issue at least, more likely to be true.

Further Reading

If you'd like to study this issue further, take a look at one or more of the following books. They each help answer the question of how we can know whether or not something is true.

James W. Sire, Why Should Anyone Believe Anything at All? (Downers Grove, Ill: InterVarsity Press, 1994).

Basil Mitchell, The Justification of Religious Belief (New York: Oxford University Press, 1981).

C. S. Lewis, Mere Christianity (New York: Macmillan, 1963).

J. P. Moreland, Scaling the Secular City (Grand Rapids: Baker Book House, 1987).