As I told you before, whenever you run into somebody with doubt in the Gospels, they are believers. Doubt is an issue with people who believe. It’s a matter of completing their faith.

Doubt is something that occurs among immature believers. It can also occur among very mature believers, but in that case it’s sinful, whereas doubt in the case of a young or immature believer may not necessarily be sinful.

Honest doubt is not a bad starting point. It’s just a bad finishing point.

In fact, the capacity to doubt is connected to rationality. It’s connected to being created in the image of God. God is a rational being and when He created man, He created man a rational being. And part of rationality is to be able to discern what is true and what is not. That is absolutely critical to God’s plan, isn’t it? If God creates people to whom He’s going to reveal truth, then it’s absolutely essential that He give those people the apparatus to sort out information to come to a correct conclusion. One of the features of that sorting process is doubt — or, if you will, a healthy kind of skepticism.

I know from a personal standpoint that doubt has served me well through my life, particularly when I was very young. I tended to be skeptical about what people said. And so I tried to follow a pattern that I learned about fairly young as a Christian, in Acts 17:11 — a pattern that was established by a group of Jewish believers in a town called Berea. When they heard the gospel, it says they received it with eagerness, but then they searched the Scriptures to see if these things were so. That’s a healthy skepticism.

If you come to my door trying to sell me snake oil, you’re going to be met with doubt. Doubt will serve you well the next time you go to the used car lot. Doubt in that sense is a very good gift. When somebody is called gullible, that’s not a compliment.

So we’re not talking about having all the evidence and not coming to a reasonable faith; we’re talking about an honest kind of doubt that serves you very well. I really do believe that God has wired us with a certain measure of skepticism for the sake of self-protection. You know not to trust everybody and everything. And people who do are seriously wounded by it, spiritually and even physically.

Some of the great heroes of the faith were pretty monumental doubters to start with. Abraham was filled with doubt when God told him that he was going to have a son. He doubted that seriously, since he was 100 years old and had never been able to have children. He had a healthy case of doubt. But Abraham is now known to us as the father of faith. What started out as doubt, having been resolved by God, then transformed itself by God’s power into faith.

Sarah, when she was told she was going to have a child, laughed with a serious case of doubt. Sarah, of course, eventually did bear that son of promise that God had pledged she would bear, and her doubt became faith, and she too is included among the heroes of faith in Hebrews 11.

Then you have Moses. Moses had a very formidable case of doubt. When God told him to lead Israel out he said, “I can’t do it. I’m not a very good speaker.” And Moses became the greatest leader in Israel’s history.

Abraham, Sarah, and Moses are given the greatest portion of Hebrews 11 in describing those people whose lives are marked by the most monumental faith. And that chapter also has a whole lot of other names of people who experienced periods of doubt in their lives, but who ended up as great monuments to faith.

Zechariah, the father of John the Baptist, certainly doubted his capacity to give birth to a son late in his life. When he was told that he would be a father in old age, this was something beyond his capability to believe. He began a doubter and ended up a man of great faith who gave a magnificent tribute to the Messiah at the end of Luke 1.

And then you have among the apostles the most famous doubter, Thomas. Thomas, unfortunately, is saddled with the label of being a doubter. But the fact of the matter is that Thomas is the one apostle who made the most unequivocally clear statement about who Jesus is of any of the apostles. It was Thomas who said concerning Jesus, “My Lord and my God.” There can be no greater statement made. One who was labeled a doubter became the man who made as great a confession as is made in the gospel accounts.

Doubters, whether in the Old Testament or New Testament, can become heroes of the faith. Doubt, then, is a good place to start. It’s just not a good place to finish.

This post is based on a sermon Dr. MacArthur preached in 2001, titled “Why the Believer Doubts, Part 2.” In addition to serving as the pastor of Grace Community Church and the voice of Grace to You, Dr. MacArthur is the chancellor of The Master’s University in Santa Clarita, Calif. You can learn more about TMU at masters.edu.