Even though I was once a blasphemer and a persecutor and a violent man, I was shown mercy because I acted in ignorance and unbelief. 1 Timothy 1:13 (NIV)
Doubt is not the absence of faith; it is the questioning of faith. You can only doubt what you already believe. When a Christian doubts, he fears God may not exist. The Christian believes there is a God, and when he doubts, he questions what he believes.
When an atheist doubts, he fears God may exist. The atheist believes there is no God, and so by definition, a doubting atheist would be someone who was questioning his unbelief. When a communist doubts, for instance, he questions Karl Marx’s vision of the utopian society.
Doubt presupposes some kind of faith. You have faith with questions. That is what doubt is, and it is one of the most common struggles in the Christian life.
Since you can only doubt what you already believe, doubt and unbelief are very different, and it is crucial to grasp this difference. Doubt is questioning what you believe. Unbelief is a determined refusal to believe. Doubt is a struggle faced by the believer. Unbelief is a condition of the unbeliever.
Unbelief involves spiritual blindness, and a determined resistance toward God. When Paul was persecuting believers, he acted in ignorance and unbelief. Ignorance says, “I cannot understand the truth,” while unbelief says, “I was deeply resistant to the truth.”
That was his condition, and the only cure for it was what happened on the Damascus Road when he was wonderfully converted. He discovered Jesus is Lord, and the whole disposition of his soul was changed by the power of the Holy Spirit. He moved from a position of unbelief to a position of faith.
Would you say you have a bigger problem with doubt, ignorance, or unbelief? Why?