At the day of judgment, no one will be able to excuse their unbelief in God by appealing to ignorance. Today, R.C. Sproul explains that atheism is not an intellectual matter but a moral one.
Paul says that the invisible attributes—His eternal power, His divine nature—have been clearly seen and understood through, by means of, what has been made so that they are without excuse. See, this is not simply an amoral, intellectual question. The question of your affirmation or denial of the existence of God is a matter of consummate moral culpability.
What excuse is the Apostle pulling away from the atheist here? The one excuse that every atheist, that every agnostic, will want to use on the final day of judgment is the excuse of ignorance. “God, I didn’t know You were there. If I just would have known, I would have believed You. I would have followed You. I would have obeyed You.” What’s worse than hardcore atheism is allegedly softcore atheism, which goes under the guise of agnosticism. The agnostic says, “I’m not going to say there is no God. I just simply don’t know whether there’s a God, because I don’t think there’s sufficient evidence to come to a conclusion one way or the other.” That terrifies me when I hear somebody say that. I say, “Because what you’re saying now is not only you’re not willing to affirm the existence of God, but you are pinning the blame of that unwillingness on God Himself for not giving you sufficient information. Be careful here. You are adding insult to injury. If this is true, then what it is saying here is that God has so clearly, clearly manifested Himself ever since the creation of the world, through everything that is made, that you can never use ignorance as an excuse before God. What Paul is saying is that people claim ignorance as an excuse, but it is a fraudulent claim.” I’ve seen real hostility emerge in discussions with people who are hostile to Christianity, and we discuss these matters.
I say, “You’re not responsible to me to believe this. You may be responsible to God to believe this, but you’re not responsible to me to believe that. You don’t have anything to fear from me. I’m not going to persecute you or prosecute you or try to bring any harm or injury to you about these things. But what I’m reading here is that in the final analysis, the affirmation of the existence of God is not an intellectual question. It’s a moral one. And if you refuse to affirm the existence of God, you are in moral difficulty with the God you refuse to affirm, if Paul is telling the truth.”
Here’s the crowning, crushing indictment. Verse 21, “For even though they knew God, they did not honor Him as God or give thanks, but they became futile in their speculations and their foolish heart was darkened. Professing to be wise, they became fools.” And notice what he says here, that the fundamental sin of the human race, the most basic crime that all of us have committed against God, that at the very time we knew of His existence, we refused to honor Him as God. We refuse to give proper gratitude to our Creator. You see, the problem with the atheist according to Paul is it’s not that the atheist doesn’t know God. The problem is he refuses to acknowledge what he knows to be true.