A few years ago I hosted a student debate at my church. Three of my high school students debated three students from the local freethinking club on the historical Jesus, intelligent design and morality. The church was packed!

One of the freethinking students argued that there is no universal moral law, and hence no need for a God to ground it. As best as I can remember, he argued that morality is merely subjective and depends upon the individual or society.

But then, interestingly, during his closing speech, the same student used the opportunity of being at a church to rail against Christians for being hateful, bigoted and intolerant. In other words, he berated Christians for being immoral.

While I couldn’t say anything, since I was the moderator, I was hoping my students caught the contradiction. Do you see it? If there is no universal moral law, as he claimed in his initial speech, and morality is merely subjective, then how can he judge Christians for being immoral? In one speech he claimed that morality was subjective, but then in another speech he criticized Christians for failing to follow the objective moral laws of tolerance and love. Which is it?

Morality is Subjective, You Bigot!

The reality is that this young man held a worldview that denies objective morality. But he couldn’t consistently live it out. As Romans 2:14-16 says, he knows there is an objective moral law because it is written on his conscience, even if his worldview says contrary.

Here’s the bottom line: Even though he claims not to believe in God, he is still made by God and lives in God’s world. If God exists, then we would expect to see people who reject God, yet who live in the world God created, live out truths that reveal their knowledge that God is real. Like a light shining through the clouds, their behavior reveals that they actually inhabit the world God has made.

My Determined Behavior is Better Than Yours!

Consider another example. In his book Free Will, Sam Harris says, “Free will is an illusion.” We may think we are free, but according to Harris, our intuitions are illusory.

But this raises some troubling questions for Harris, since he has written some other books morally condemning the teachings of the Bible and the behavior of Christians. Is he being inconsistent, like the students above?

After all, if determinism is true, then Christian teachings are merely the result of some natural process involving law and chance. They were not intentionally developed, but are the result of blind, material processes. So on what basis can Harris condemn them for being wrong? Since chemicals don’t have plan, purpose or any kind of teleology, in what sense are they wrong?

And why condemn the behavior of Christians or other religious folks? After all, they didn’t decide to engage in the Crusades or the Inquisition. Rather, their behavior was the result of genes, chemicals and other natural forces. They couldn’t have done any differently! In fact, according to his deterministic views, their “wrong” behavior is just as determined as his moral protest. What makes his behavior “better” than theirs?

I am certainly not defending immoral behavior done in the name of Christ. Nor am I claiming that atheists are more immoral than Christians. That’s not my point. My point is that, as Kant argued, the claim that we ought to do something implies that we can do it — morality requires free will. And since Harris denies free will, he contradicts himself when making moral condemnations.

As with the students above, he cannot consistently live out his atheist worldview. His actions reveal that he really does believe in free will, even if his worldview leads him to claim otherwise.

Living in God’s World

Other examples could be given about the existence of human value, the objectivity of beauty and more. But my point is simply that we know what people really believe not by what they say, but by how they really live. Like a ray of light shining between clouds, people reveal their true beliefs through their actions.

Many people claim not to believe in God, but in my experience, it’s only a matter of time before their lives betray them. Why? Remember, even those who don’t believe in God still live in the world God created. It’s inescapable.

Sean McDowell, Ph.D. is a professor of Christian Apologetics at Biola University, best-selling author, popular speaker, part-time high school teacher and the Resident Scholar for Summit Ministries, California. Follow him on Twitter: @sean_mcdowell and his blog: seanmcdowell.org.

Originally appeared at seanmcdowell.org. Reprinted with permission.