What does Mark 14:46 mean?

The irony in this verse is profound. "Seized" is from the Greek root word krateo. It means to have power over, to become master of. Despite what the Sanhedrin thinks and the disciples fear, the guards are not in control of the situation.

About four thousand years before this, Adam and Eve disobeyed God and condemned all their descendants to an eternity separated from God. God responded with appropriate curses for the snake, Eve, and Adam. But He also gave the "protoevangelium": the first message of good news. In Genesis 3:15, God tells the snake that Eve's offspring will bruise or crush Satan's head. Jesus came to earth for this specific moment and the hours that follow (1 John 3:8). God lives outside of time, as did Jesus before the incarnation. Jesus knew that He would have to die for His creation as He was creating the world. God orchestrated this moment, not the guards, Judas, or the Sanhedrin.

Jesus communicates this to Judas. When Judas kisses Him, Jesus says, "Friend, do what you came to do" (Matthew 26:50). If Judas is still possessed, Satan must be confounded by Jesus' passivity. In the trials to come, before the Sanhedrin (Mark 14:53–65), Pilate (Mark 15:1–5), and Herod Antipas (Luke 23:6–16), Jesus takes an interesting tact. He points out His judges' hypocrisy and admits to His identity; in the garden, when asked if He is Jesus of Nazareth, His admission is so powerful the guards fall to the ground (John 18:5–6). But Jesus never defends Himself against the false charges, fulfilling the prophecy of the Suffering Servant (Isaiah 53:7).

As the guards seize Jesus and take Him to the chief priest and beat Him (Mark 14:65), as the disciples run into the night (Mark 14:50) and Peter denies Him (Mark 14:66–72), Jesus is still in control. As He says in John 10:17–18, "…I lay down my life that I may take it up again. No one takes it from me, but I lay it down of my own accord. I have authority to lay it down, and I have authority to take it up again. This charge I have received from my Father."