I appreciate the fact that John doubted. What I mean is that here is the forerunner of the Messiah, the one taking up Elijah's prophetic mantle, the one filled with the Spirit from the womb of his mom, and a doubter. His circumstances strained his faith. I'm like that. I get it. So I appreciate his doubt.
John was in prison. He was lonely and frustrated and wondering about why bad things happen to good people. But deeper in his gut, wrenching at the heart of the prophet, was the question of if he had been wrong. It's one thing to sit in prison as a prophet - you actually kind of expect it (or if you don't you should). Bad things happen to those who speak for God. Martyrdom is the most popular end. It comes with the calling.
But this question haunted him. What if he was wrong about Jesus? What if he had pointed people to an unMessiah? What if he had blurred the message? It's one thing to die as a prophet of God. It's a whole different thing to be wrong as one.
And I think that's where the questions come. And I appreciate the answer from Jesus. Because when asked, Jesus didn't give a verbal answer first. He healed a lot of folks. Then he told John's friends to tell John what they had seen. I think if we're honest in our doubt, honest with God about it, and still seeking to honor Him in it, God's general inclination is to strengthen our faith by letting us see what we need to see to keep believing.
But that's just me thinking thoughts...