Given that “doubt” is considered the opposite of “faith,” it is not uncommon for Christians to presume that “doubt” is therefore always sinful. But my suggestion here is that this is not really true. I think that we should consider the opposite of “faith” to be “disbelief” and not “doubt.” While some might consider this distinction to be a bit nitpicky, I think that the positive work of doubting has not always received a fair shake. It should be clear to us that many people come to faith in Jesus Christ precisely because they began to doubt that their godless lifestyles have much meaning. Many come to faith in Jesus after a long period of doubting that following after the gods of this world will lead to fulfillment. Thus, it seems rather plain that “doubt”—especially doubt that is guided by the Spirit of God (!)—can serve God honoring purposes. So, what exactly do we mean by the term “doubt”?

In an article on the concept of doubt, theologian John S. Feinberg distinguishes four different kinds of this intellectual posture: skeptical doubt, provisional doubt, denial, and ignorant doubt (see “Doubt” in the Evangelical Dictionary of Theology [Baker, 2017]). We can find examples of each of these in our current day, and each is also exemplified for us in the pages of Scripture.

Skeptical Doubt is occurring when a person says, “I can’t be certain for there is no way to know.” Such skepticism suggests that the truth is simply not available for people to grasp. A possible example of skeptical doubt in Scripture is found in Pontus Pilate in John 18:28–40; when Jesus claimed, “Everyone who is of the truth listens to my voice,” Pilate responded to him, “What is truth?” (v. 38). With skeptical doubt, a person frankly cannot learn.

Unlike skepticism, denial is the kind of doubt that admits knowledge is possible, but it is so entrenched in previous viewpoints that it refuses to examine the evidence on hand so as to learn from it. “I don’t care what the evidence says, this item is not true.” This kind of doubt is exemplified in the New Testament by some of the Jewish religious leaders in John 12:9–11; they were so determined to oppose faith in Jesus that they wanted to get rid of some of the evidence: “So the chief priests made plans to put Lazarus to death as well, because on account of him many of the Jews were going away and believing in Jesus” (vv. 10–11). When committed to presumed ideas, a person in denial refuses to learn.

Ignorant Doubt is a soft version denial; it admits to the evidence on hand but insists that more evidence is needed even though it is ignorant of what that additional evidence would be. By taking what appears to be a humble approach to its denial of God’s existence, agnosticism displays its ignorant doubt by saying that is does not yet have all the evidence it desires: “I see enough evidence to believe, but I want to look for more evidence before actually deciding.” In a parable about the afterlife of a rich man (Luke 16:19–31), the man described his five brothers as people with ignorant doubt who needed just a little more evidence to believe in God and so to avoid the eternal damnation that the rich man was experiencing. When Abraham responds, “They have Moses and the Prophets; let them hear them,” the man objects, “No, father Abraham, but if someone goes to them from the dead, they will repent.” But to this Abraham replies, “If they do not hear Moses and the Prophets, neither will they be convinced if someone should rise from the dead” (vv. 27–31). When stuck in ignorant doubt, a person simply won’t decide to learn.

While the failings of the previous forms of doubt are self-evident, it is the fourth form of doubt that we must be careful not to confuse with its sinful counterparts. Provisional Doubt occurs when a person says, “I am unsure about this, but I want to find an answer based upon the evidence.” This is commendable and not sinful. An important New Testament example of a person with this kind of doubt is John the Baptist in Luke 7:18–35. John had already identified Jesus as “the Lamb of God, who takes away the sin of the world” (John 1:29) and had been encouraging people to follow Jesus rather than himself (see John 3:30). But now John was sitting in prison, and this was not what he had envisioned for himself when the Savior of the world was at hand (!). So, understandably, he began to question Jesus’s identity. What did John do with this question? He sought an answer by sending messengers to Jesus. “Are you the one who is to come, or shall we look for another?” (Luke 7:20). In responding to John’s messengers, Jesus did not give a simple “yes” or “no” answer; instead, Jesus listed the things that were being done, and told the messengers to simply report those things back to John. Jesus knew that the list of miraculous items (Luke 7:22–23) comes right out of the Old Testament prophecies of Isaiah and that John could be trusted to recognize this evidence as the positive answer to his question about Jesus.

What is particularly encouraging about Jesus’s interaction, however, is what Jesus says after John’s messengers depart. Rather than roll his eyes about what some might consider a silly question, Jesus actually defends John the Baptist. A “reed shaken by the wind” (v. 24) would be a name for a doubter with silly questions, someone vacillating from his former commitment, someone weak and undependable (see 2 Kings 18:21; Ezek. 29:6–7). Jesus, however, points out that John is not a weakly person accustomed to the creature comforts of the rich. In fact, John is in far worse circumstances now than when the people had last seen him. No, John is no willy-nilly doubter; he has been devotedly watching for the Messiah with a faith that says that, if it’s not Jesus, it definitely will be someone. And so, Jesus does not ridicule John for asking an honest question; on the contrary, Jesus compliments John! Jesus announced that John is not a mere prophet; he is more than a prophet. He is the one that the Old Testament talks about as the forerunner of the Messiah (Luke 7:24–27; citing Mal. 3:1).

And then Jesus goes a little further in His complimenting of John the Baptist: “I tell you, among those born of women none is greater than John. Yet the one who is least in the kingdom of God is greater than he” (Luke 7:28). None is greater than John the Baptist, and even he has questions. But John was willing to look in the right places for the answers. If we have questions and doubts, we should do like John and look to Jesus and the Scriptures for the answers to those questions. So it is that a person with provisional doubt is someone who wants to learn.

Thus, I think we can see that doubt is not always a sin. Yes, refusal to believe the truth is a sin, and some other forms of doubt are also sinful. But there is a kind of doubt—provisional doubt—that asks questions in the search for truth and that God uses to bring people to clearer answers. May God turn all our doubts into provisional ones that increase our faith in Him.