Jim Spiegel, a colleague of mine at Taylor University, published a book last year titled The Making of an Atheist. In the book he contends that the rejection of God is a matter of will, not of intellect. He suggests that immoral behavior leads to an inability to see the clear evidence for the existence of God. Atheists choose to reject God for psychological reasons such as the lack of a loving human father and because they do not want a God to exist to whom they would be accountable for their immorality.
Not surprisingly, his book did not go over very well with the atheist community, but there is the seed of an idea there that suggests a way ethics can be used to draw those who reject God toward truth about God. Many who reject God still believe that there are things that are intrinsically right and wrong. While a desire not to be subject to ethical standards leads a person to atheism, the understanding that there are ethical standards is the first step toward God.
So the next time someone who does not believe in God disagrees with you on an ethical issue commend them for their belief that morality is something to be concerned about. Taking morality seriously can be the first step toward the one who is the source of all that is good.