John had second thoughts about Jesus. 

Herod had tossed John in jail. Sitting in the dark amid filthy straw on the floor of a windowless cell, John had plenty of time to think back on the ministry that had gotten him into this fix.
His focus had been crystal clear. The Messiah was coming. Everything he did, and everything he said, was devoted to preparing himself and the people of Israel for the Messiah’s arrival.
Edward Hopper’s “Hotel Room”
John lived in strict self-denial. A backwoods hovel served as his home address. His wardrobe consisted of tattered, ill-fitting castoffs. And he foraged for food that many of us would use Roundup to kill and call Orkin to exterminate.
His sermons were hair-raising, guilt-inducing, and terrifying rants.
Riled by what he saw as his listeners’ moral laxness and spiritual insincerity, John called them a bunch of snakes. He was sure that the Messiah’s coming meant a final settling of accounts. God’s wrath would consume those that didn’t measure up. 

So John’s message to the crowd was clear. Clean up your act before it’s too late.
Jesus had come to John to be baptized. John initially balked. Here was the Messiah that he’d been waiting for. Surely Jesus should baptize him. But Jesus insisted and John relented.
We don’t know much about John’s ministry from that day on. He ran afoul of Herod, criticizing him for marrying into the family. His persistent bluntness landed him in the royal dungeon.
Before his arrest, John probably heard, or at least heard about, Jesus’s teaching. Even more to the point, John likely heard reports about Jesus’s actions.
Renoir’s “The Luncheon of the Boating Party”
In contrast to John’s ascetical severity, Jesus was a regular party guy. And it’s not just that he ate and drank enough for religious leaders to call him a glutton. It was the company he kept. Tax collectors. Women of ill repute. Deadbeats. Cynical hipsters. Shady hedge fund managers.
These were the very people that John had scolded. The Messiah was supposed to mop the floor with the moral slobs and spiritual bums. And here Jesus was eating dinner with them like they were joined at the hip.
All of this gave John serious second thoughts. So, from his darkened cell he sent some of his followers to put the question directly to Jesus himself. Are you really the Messiah? (Luke 7:20)
Frederick Buechner paraphrases Jesus’s response like this:
“You go tell John what you’ve seen around here. Tell him there are people who have sold their seeing-eye dogs and taken up bird-watching. Tell him there are people who’ve traded in aluminum walkers for hiking boots. Tell him the down-and-out have turned into the up-and-coming and a lot of deadbeats are living it up for the first time in their lives. And three cheers for the one who can swallow all this without gagging” (Luke 7:22-23).*
We don’t know what John thought of all this. But we do know that, for John and probably for many of us, accepting Jesus as the Messiah includes coming to know a God that we have misunderstood in a very big way. 
And since Jesus is the Messiah, his words and actions tell us what salvation looks like. And it doesn’t look anything like what many of us have been assuming.
More than a few Christians assume that God relates to us principally as a judge. We are on this planet for a relatively short time. Our purpose in this life is to reach the level of moral achievement needed to meet God’s approval. When we meet God’s approval, God lets us into heaven. Hell awaits those who don’t pass the test.
Timothy Keller refers to this as the moral performance narrative. The focus of this distorted version of the Gospel is our capacity to achieve a high enough level of moral achievement to be acceptable to God. Keller calls this the Good Rules version of the Gospel. This contorted Gospel tells us what we must do.
James Tissot’s “The Return of the Prodigal Son”
But the Gospel is Good News. News reports what has already been done, not what must be done in the future. The Good News is that in the life, death, and resurrection of Jesus, God has already restored us to relationship with God and with all of God’s children.
Jesus shows us that God resembles the prodigal son’s father, not the grim reaper. God runs to us in our boneheadedness and embraces us even when we could use a hot moral shower. 
God’s embrace heals us. God does not stand at a distance, waiting for us to clean up our act. God invites us to a heavenly banquet before we have time to change our clothes and wash our hands.
John seems to have misunderstood even his own words. He was so insistent about living a changed life, that he forgot how we would get there. 
John himself had said the the Messiah would come baptizing in the Holy Spirit and fire. Maybe he meant that God would put us all in our place once and for all. But Jesus shows us the true meaning of those words.
Edward Hopper’s “Automat”
In Jesus God bridges the infinite gap between our finite, messy lives and the infinite, perfect glory of divine life. God holds us accountable, but not with wrath. God holds us accountable with mercy. With compassion.
In Jesus, we see that God’s mercy is not judgment withheld or softened or diverted. Mercy is the healing, reconciling love of God poured out in shameless extravagance.
God’s love transforms the lives it touches. God’s own mercy flows through God’s beloved. That’s what a life that bears fruit worthy of repentance looks like. 
We feed the hungry. Clothe the naked. Visit the sick. We house the homeless and release the captive.
We forgive offenses, hold each other accountable for love with love, comfort the afflicted, and afflict those whose comfort comes at the expense of others.
This is hard, sometimes dangerous, and frequently heartbreaking work. Jesus’s way of mercy can give each of us second thoughts. But it is the only way out of the prison of a hardened, lifeless heart.

*From http://frederickbuechner.com/content/john-baptist; originally published in Peculiar Treasures and then republished in Beyond Words