After Jesus was arrested he was put on trial at night (illegally) where false witness was brought against him. When the High Priest demanded under oath, by the living God, to say if he was the Messiah, Jesus told the truth and for it was declared a blasphemer. They hit him, slapped him and spat upon him. Because Jesus told them who he was, they wanted him dead, but they no longer had that power. They had to get the Romans to kill Jesus for them.
Did the Roman's Kill Jesus?
The Jews brought Jesus before Pilate charging Jesus with saying he was the King of the Jews. That would have been a treasonous act since only Rome could declare who the King of the Jews would be. Pilate found Jesus innocent but the Jews demanded that Pilate crucify Jesus saying, "His blood be on us and our Children."
Pilate had Jesus scourged 39 times which ripped the skin off his back down to the bone. He was beaten, slapped, spat on, ridiculed, hit with reeds, and a crown of thorns placed on his head. He then had to carry his cross to the execution point but was too weak from the abuse he had taken and collapsed on the way. The Roman's hammered nails into his hands and feet, and hung him on a cross. He hung there naked in the sun for hours before he died. To make sure he was dead a soldier thrust a spear into his side.
Jesus said that neither the Jews nor the Romans killed him. "No one takes it from me, but I lay it down of my own accord. I have the authority to lay it down and the authority to take it up again. This command I received from my Father." John 10:18
No one could have taken the life of Jesus unless he willed it so. Why would he do such a thing?
I killed Jesus.
I am the one who was condemned him to death. Jesus was innocent but I was guilty. I rebelled against God. My heart was filled with evil. I am the one whose death sentence was justified.
Jesus took my place and died so that I might live. It was for me he was tortured and killed. If not for my sin, he would never have needed to die. The blame is not to be given to the Jews or the Romans, but to me.
"For Christ also suffered once for sins, the righteous for the unrighteous, to being you to God. He was put to death in the body but made alive in the spirit." 1 Peter 3:18