What does Mark 15:14 mean?
Pilate's question is significant. Jesus has cowered the chief priests (Mark 11:27–33), threatened the elders' financial interests (Mark 11:15–19), embarrassed the Sadducees (Mark 12:18–27), and shamed the Pharisees (Matthew 23:1–36). He even affirmed Caesar's authority (Mark 12:13–17). Despite what the Jewish leaders claim, Jesus has not disrespected Caesar, planned a rebellion, or caused any political unrest. Even when Jews tried to make Him king, He slipped from their grasp (John 6:15).The accusation that most condemns Jesus by the Mosaic law is the issue the Jews didn't think Pilate would be interested in—but it's actually the claim which scares Pilate the most. When Pilate sarcastically dares the Jews to crucify Jesus, themselves, they finally reveal their religious motivation: "We have a law, and according to that law he ought to die because he has made himself the Son of God" (John 19:7). To the monotheistic Jews, this is a clear case of blasphemy (Mark 14:61–64).
This presents another wrinkle to Pilate's judgment. The polytheistic Romans believe the emperor is a god and gods come to earth and impregnate human women. So, as interpreted in Pilate's Greco-Roman worldview, the "son of [a] god" claim is very possible, and it scares him (John 19:8). Upon Jesus' death, the centurion affirms Pilate's fear, saying, "Truly this man was the Son of God!" (Mark 15:39).
But more than the legal and logical conundrums, Pilate's question is imperative for the legitimacy of the gospel. Jesus did nothing to deserve death, and that is why He is the perfect sacrifice for our own death-deserving sins.
Despite Pilate's clear reluctance to crucify Jesus, he is not a "nice" man by any definition. After he used money dedicated to the temple to build aqueducts, a group of Jews peacefully confronted him, holding a kind of sit-in for a week. When he finally came to speak to them, he posted soldiers in the ranks of the Jews, their armor covered. At a signal, the soldiers drew clubs and knives and beat the protestors. Some died from the beatings while others were trampled. This is one of several times Pilate showed his cruelty to his subjects.
Some time after the sham trial of Jesus, Pilate will be removed from rule when he massacres a group of Samaritans. They had been tricked into thinking they were digging up sacred artifacts left by Moses. The gathering didn't have anything to do with a rebellion, but Pilate sent his army to chase down the group and kill those they could catch.
Overly aggressive or not, Pilate is willing and able to confront the slightest challenge to his authority. He knows Jesus is no threat.