His death was a total submission indeed; not that He did not have power to command legion of angels to come and fight on His behalf; but He voluntarily gave Himself up as a Paschal lamb to be slaughtered, in order to be able to take away the sins of the world. In order for Him to surrender to the sacrificial death of the cross that brought about salvation: He opened not His mouth; He was brought as lamb to the slaughter, and as sheep before His sharers is dumb; so, He opened not His mouth
Isaiah 53:7 He was oppressed, and he was afflicted, yet he opened not his mouth: he is brought as a lamb to the slaughter, and as a sheep before her shearers is dumb, so he openeth not his mouth.
He submitted Himself to be arrested of the people. His major aim was to lay a foundation of salvation through His shed blood on the cross of Calvary; since this was the only means God could use to save man. It was an agreement between Him and the father to come and die; that man who was under bondage of sinfulness could be saved. For that, there was no other alternative than for Him to give Himself up to be crucified. At Gethsemane, He prayed earnestly, saying,
Matthew 26:39 And he went a little farther, and fell on his face, and prayed, saying, O my Father, if it be possible, let this cup pass from me: nevertheless not as I will, but as thou wilt.
His death was to fulfill the will of His father in saving man whom He created in His image.