Any sports competitor knows that sometimes the best offense is to set the opponent up to make his own mistakes. You don’t have to beat him or her as much as you need to let him beat himself. Find his weaknesses, exploit them, and let him make his own mistakes.
Any trial lawyer will tell you the same thing. You need to rattle the witness so that he loses his composure and blurts out things that are harmful to his own case or his own testimony. If you can shake his confidence, you can shake his case.
I see the same dynamics happening here. The guards mock him, perhaps just hoping that he’ll lunge at them in anger, verbal abuse, or vengeance. They beat him, hoping to wear him down to the point where he’ll say anything to make the pain stop. He’ll admit to whatever you ask if you please don’t hit him again. Not only does such beating fulfill the abusive power desires of the guards, but it can also work to motivate a confession out of the prisoner and hopefully shorten the proceedings so we can all be home in time for supper.
Then they play on his religious claims. “Oh, we have a prophet here, do we? Tell us which one knocked that tooth out, O Great One!” If you knew everything, you would have avoided this beating. If you were really deity you’d stop it. If you were a prophet, you’d have something to say in judgment of us. “But you just take it like a door mat.” The alleged man of God is nothing but a failure like everyone else in a “trial by thrashing”. Big man has nothing to say now.
This goes on through the night, one abusive minute after another, hour by hour. Jesus doesn’t break. He is brought back before the authorities. “Let’s make this easy,” they smirk. “If you’re the Messiah, just say so.” They’re looking for self-incrimination, for surely he’ll say something they can catch him on, so they think.
“You won’t believe anything I say,” Jesus responds, “and you won’t tell the truth if I ask. But after this, I’ll be at the right hand of God, if you really want to know.”
“So, by your own confession you claim to be the Messiah, human, and divine. Are we hearing you right?”
“Yes, you are,” Jesus confidently responds. Interestingly, the only confession they get out of him is calm and confident authority and a claim to deity.
Well, in their minds it’s blatant blasphemy, enough to condemn him to death. It’s what they wanted: for him to condemn himself by his own words. Of course they’re right if Jesus is not what he claimed to be. Otherwise, ironically enough, they are condemning themselves by their own words.