"The I AM"

 "As soon then as he had said unto them, I am he, they went backward, and fell to the ground." (John 18:6 KJV)

  "God replied to Moses, "I AM Who I AM. Say this to the people of Israel: I AM has sent me to you,"" Exodus 3:14 NLT)

 As to the whole willing servant thing, Jesus was a willing servant, from the time He was formed in His mother's womb; but in this moment, He was the LORD of Heaven's Armies, determined and set to take on the most important task to all of all mankind. From here on out, He shall be the Lamb of God, being led to the slaughter; the Creator of Heaven and Earth, sacrificed for the world that He created! 

 Yes, He was continuing to serve His Father; but from here on out He only needed to be humble and take whatever they dished out. This incident that John is showing proves that Jesus had given up any Divine power, offering Himself to be taken freely and voluntarily giving Himself over to them.

 Imagine what He could have done, had He resisted! Just look at Elijah, what he had done when Israel's king had sent groups of fifty men to capture him; and he was just a prophet...

"When the messengers returned to the king, he asked them, "Why have you returned so soon?" They replied, "A man came up to us and told us to go back to the king and give him this message. 'This is what the LORD says: Is there no God in Israel? Why are you sending men to Baal-zebub, the god of Ekron, to ask whether you will recover? Therefore, because you have done this, you will never leave the bed you are lying on; you will surely die.'" "What sort of man was he?" the king commanded. "What did he look like?" They replied, "He was a hairy man, and he wore a leather belt around his waist." "Elijah from Tishbe!" the king exclaimed. Then he sent an army captain and fifty soldiers to arrest him. They found him sitting on top of a hill. The captain said to him, "Man of God, the king has commanded you to come down with us." But Elijah replied to the captain, "If I am a man of God, let fire come down from heaven and destroy you and your fifty men!" Then fire fell from heaven and killed them all. So the king sent another captain with fifty men. The captain said to him, "Man of God, the king demands that you come down at once." Elijah replied, "If I am a man of God, let fire come down from heaven and destroy you and your fifty men!" And again the fire of God fell from heaven and killed them all. Once more the king sent a third captain with fifty men. But this time the captain went up the hill and fell to his knees before Elijah. He pleaded with him, "O, man of God, please spare my life and the lives of these, and your fifty servants. See how the fire came down and destroyed the first two groups. But now please spare my life!" Then the angel of the LORD said to Elijah, "Go down with him, and don't be afraid of him." So Elijah got up and went with him to the king." (2 Kings 1:5-15 NLT)