Author R.C. Sproul Jr. has a "doctorate" in the non-subject of Theology. It shows. Here are his five things for Christians to remember when they converse with atheists. What's wrong with this picture?
"1. There are no atheists. Romans 1 tells us that unbelievers suppress the truth of God’s existence in unrighteousness (vs 8). They want not to believe, but they know there is a God, and know that they stand guilty before Him. Do not think you are dealing with a disinterested scholar who is just lacking good information. You are dealing with someone angry and frightened, someone rightly terrified over his own guilt. If they get angry, chances are they are angry at God more than you. No matter how smart they may be, they are more afraid of you than you are of them.
"2. Their deepest need is to deal with their guilt. The best thing about dealing with atheists is we not only have what they need, but we have what they know they need. That is, because they dread their guilty standing before God they are ripe for hearing about Jesus’ solution to our guilt problem. Denying His existence is just whistling in the dark. Repenting of our sin, on the other hand, is singing in the heavenlies. As you remember point one, keep coming back to the atonement of Christ, and the offer of forgiveness for all who trust in His finished work.
"3. They are using our stuff. Their worldview allows for no transcendent morality, or purpose. But no one can live this way for ten seconds. Even their participation in the argument is grounded on the premise that it is better (a concept that is meaningless if we are grown up germs) to believe the truth than a lie. On the one hand this should be cause for hope. This borrowing that they do happens because of the remnants of the image of God in them. On the other hand, never let them forget that they have no ground to stand on, that they can’t even participate in the argument without conceding transcendent morality and purpose.
"4. As with point number 3, every time they express a moral judgment against you, or the Bible, or believers, remind them that such is out of bounds based on their foundation conviction. If there is no God, then my moral perspective is as valid as theirs. Do not be shy of using their assumptions on them. When they judge you for judging, point out that they are judging you. Remind them that they shouldn’t be privileging their own narrative against yours. This not only confuses them, but shows them that you are familiar with their tactics and won’t be intimidated by them.
"5. Remember such once were we. The difference between the believer and the atheist is not found in the believer’s superior character, more astute mind but in the grace of God alone. Without the grace of God in our lives we would be as caught up in folly, as self-referentially absurd, as blazingly hypocritical. Indeed even with His grace we are often guilty of these sins. It is sin, not stupidity that is the root of all our problems, and what sets us as believers apart is the glory and power of repentance. Don’t be shy about owning your sin. Jesus isn’t. Be bold about the truth, humble about yourself."