There is always something missing
When people had in front of their eyes and in their ears John the Submerger, they asked if he was the Messiah and, once finished with questions, these statements remained: John, the desert man, cannot be but a fiend.
When people had in front of their eyes and in their ears the Son of God, they didn't find anything better that reminding Jesus how, before the arrival of the Messiah, Elijah should have come, underlining therefore that Jesus, to be considered the Messiah, was in fact missing the prophet presence.
Then either Jesus wasn't the Messiah or, as a Messiah, it was coming on earth in a rather imprecise and fretful way.
Really all these questions to Jesus, all this need for details show a deep instability and incapacity to see and recognize that the prophet restorer, John the Submerger, had in fact already come.
For the human mind there's always something missing. It doesn't matter if we are talking about men or God, for the human mind there's always something missing, there's always unquestionably a lot of something missing. If the sun is out, it's too hot, if it's not out, it's too damp, if someone is generous he's hiding something, if he's not generous, he's hiding something else. If one is dedicated to the others, he'll better minding his business, if he's minding his business, he should be dedicated to others.
Black men didn't have a soul, the ones belonging to a different religion didn't have faith in the right God, the ones tortured by the Inquisition didn't have the right faith, the natives of different regions on earth didn't have progress, culture, religion, science, moral, laws. How does the mind make up for all these deficiences? With what if not with violence? Yes, what's making up for what's missing, so cleverly pointed out by the mind, is violence, it's always violence, violence fills the gaps. Violence compensates all that the mind is missing.
It fills the lack of persuasion, intelligence, reason, truth, coherence, money, abilities, authority, wisdom. The more a man is wrong, taking notes of deficiences everywhere, the more he's violent. Jesus explained it with utter clarity: But I tell you that Elijah has already come, and they did not recognize him but did to him whatever they pleased. So will also the son of man suffer at their hands.
That's it. People did not recognize John the Submerger, because, without a doubt John was missing something to really be what he said he was, the herald of Jesus. Therefore he was violently eliminated. People didn't even recognized Jesus, because, no doubt, Jesus as well was missing something to be who he said he was. And they killed him with violence. Violence is the answer to the ignorant mind that is looking for its entire life for what is missing to convince itself of what is already there.