Doubt can be a tricking thing. Our society, for instance, has elevated doubt to an unquestioned virtue. Those who follow tradition or submit to any kind of standard—especially an ancient one—are viewed with smug condescension. “Well,” we think, they may not be clever enough to question authority, but I won’t be fooled.” We’ve trained ourselves to see through everything, looking for the gimmick. But as C.S. Lewis said, “You can’t go on ‘seeing through’ things forever. The whole point of seeing through something is see something through it. To ‘see through’ all things is the same as not to see.”

Many Christians respond by asserting that doubt is a vice. It has no place in a life of faith. Questions are often discouraged, as religious leaders tell their flocks to simply believe. But this is hardly a better option. When legitimate questions are met with the command to “shut up and follow orders,” it’s not surprising that so many people walk away from the faith.

The Bible doesn’t support either of these errors. Doubt, in Scripture, can be either a virtue or a vice. On the surface, it can sometimes be hard to discern which is which. For instance, in Luke 1, the angel Gabriel visits two different people back to back—Zechariah and Mary—and promises miraculous births. They both respond with perplexed questions. But while Mary gets an explanation, Zechariah gets put in timeout for 9 months, unable to speak. What’s the difference?

Zechariah and Mary are excellent examples of the two kinds of doubt—proud doubt and humble doubt.

Proud doubt grows out of disbelief. It is defiant, looking inward at itself in bitterness. When the promises of God come, this type of doubt resists. “There’s no way this could be true.” That was Zechariah. But humble doubt grows out of wonder and awe. When the promises of God are held out for the humble doubter, she takes them—tentatively, but in amazement. “How can these things be true? I don’t understand, God…but I’m ready to learn.” That was Mary.

In a sermon on Luke 1, Tim Keller calls these dishonest doubt and honest doubt. The dishonest doubter is actually rather lazy. He doesn’t respond to God’s revelation by examining the claims. He is closed-minded, refusing to consider the possibility that something exists which could challenge his comprehension. He simply shrugs off new claims with a flippant “that’s impossible” or “that sounds dumb.” Those statements aren’t arguments; they’re blind assertions.

The honest doubter, on the other hand, will ask genuine questions. This is actually pretty risky, because if you ask a real question, it’s possible you might get an answer you don’t expect (or worse, don’t like). Real questions put the doubter in a posture of humility and vulnerability. She admits that there is more out there than she may know. What if God actually answers? And what if that answer shatters your categories? What if that answer demands more from you than you are ready to give? It takes guts to ask an honestly doubtful question of God. He might just answer.

I love Mary’s humble and honest doubt. If she hadn’t offered up her question to Gabriel, you and I would never have gotten the benefit of Gabriel’s response: “For nothing will be impossible with God” (Luke 1:37). One of the greatest, faith-building statements in all of Scripture—and it comes because Mary asks the doubting question. Your doubt may be uncomfortable, but if you’re honest about it, God may not only bless you with an answer; he may also use that doubt to bless others after you.

We all have doubts. We wonder why the world looks the way it does. We wonder why God would allow some of the terrible parts of our own lives. I’m not saying you should stop doubting. I’m saying you should doubt humbly. Are you willing to doubt your doubts? Or are they so firmly fixed in your mind that you’ve closed your mind to a God who might contradict them?

The problem is never the specific doubts. God is big enough for every doubt and every question we have. The problem is the proud and self-centered heart behind the doubts. So if you find yourself doubting, be willing to doubt with faith. Faith isn’t the opposite of doubt any more than unbelief is a synonym of doubt. Faith and unbelief have to do with the posture of your heart behind those doubts.

Charles Spurgeon said that doubt is a foot poised to go forwards or backwards in faith. We can never go forward without first picking up the foot. So stare into your doubts. But then look into the face of God, realize his power, and grasp the greatness of his love. And ask your questions. Leave room a God whose power and wisdom are far above your own and search the Scriptures to see what his answer might be. Humble doubts lead to deep faith.