When Peter tried to walk on water, he took his eyes off Jesus and sank. But Jesus picked him up, saying, “You have so little faith. Why did you doubt me?” (Matt. 14). Likewise, on our journey of faith, each of us is confronted by doubts—we cry out, “Lord, help me overcome my unbelief” (Mark 9:24). Having doubts is normal. The important thing is how we handle them.
Imagine that doubt is a fork-in-the-road of faith (we'll have many of these in a lifetime). One road leads to the resolution of doubt to greater faith. The other is a dead-end of double-mindedness (James 1:8).
Double-mindedness (not doubt) was the primal sin: “I am afraid that you will be led astray from your pure and undivided devotion to Christ just as Eve was deceived by the serpent’s craftiness” (2 Co. 11:3). Jesus attributes Martha's anxiety to double-mindedness while honoring Mary's singular attention on Him. (Luke 10:41-42). So, to the degree we fix our eyes on Jesus (Heb. 12:2), we will overcome troubling doubts and walk on the waters of bigger faith (Col. 3:2). Just like Peter did!