I do agree that the officials of the time, basically at the direction of the Jews, physically put Jesus on the cross. And of course, we all have responsibility in that without our fallen nature, it would not have been necessary for Him to die. What is so amazing is that, even though our sins can be considered the thing that sent Christ to the cross, it is only by His will that He was on it. At any time, He could have cast off the burden of the cross. But Jesus CHOSE to die for our sins, and not only that, but to suffer for us as well.
As you know, before Christ died for us, an animal sacrifice was required to atone for sin. But the animals were not first made to suffer. In fact, an animal who was sick or injured in any way would have be considered unacceptable for sacrifice. The actual death of the animal, although perhaps the most theologically significant part of sacrifice, was possibly the quickest part as well. Had Christ died only to cover our sins, it could have been quick and painless. All that was required was blood. Why then did He suffer such affliction? To set us free from it.
My pastor recently gave a really amazing sermon on this. He referred back to Isaiah 53:5. "He was pierced for our transgressions, he was crushed for our iniquities; the punishment that brought us peace was upon him, and by his wounds we are healed."
It was by his suffering that we were set free from our transgressions (our willful sins) and our iniquities (our fallen nature). He died so that we would be forgiven, but he suffered so that we could be victorious. Later, in verse 10, the prophet says that "the Lord [made] his life a guilt offering." Guilt offerings were made when someone sinned unknowingly.
In Leviticus 5:17-19, the Lord said to Moses, ."If a person sins and does what is forbidden in any of the LORD's commands, even though he does not know it, he is guilty and will be held responsible. He is to bring to the priest as a guilt offering a ram...and he will be forgiven. It is a guilt offering; he has been guilty of wrongdoing against the Lord."
It may be that this was even what Christ was referring to when he said, "they do not know what they are doing." He may have been at that point praying for forgiveness of the sins we commit unknowingly, presenting himself as a guilt offering.
As Christians, then, our responsibility is found in coming to Jesus and turning over to Him not only our sins, but all of our guilt and even our reliance on our fallen nature (from which come our iniquities). "For therefore there is now no condemnation for those who are in Christ Jesus." Romans 8:1
Hallelujah!