All humans are responsible - If you believe Bible:
For there is no distinction [between Jew and Gentile]: for all have sinned and fall short of the glory of God,
and are justified by his grace as a gift, through the redemption that is in Christ Jesus, whom God put forward as a propitiation by his blood, to be received by faith. (Romans 3:22-25)
I do believe the Bible. That all, both Jew and Gentile, are sinners and in need of salvation, is clear. That all, both Jew and Gentile, are justified by grace through faith, is clear also. That all, both Jew and Gentile, become sons of God by faith in Jesus Christ, is also clear. (Gal. 3:26-28)
Plus, the Gentiles certainly played a role in Christs crucifixion. (Acts 2:23) "...ye have taken, and by
wicked hands have crucified and slain."
But it is the house of Israel that God holds directly responsible for that rejection and crucifixion. Why? Because it is to Israel that Christ came as their Messiah. Christ's message at the beginning of His ministry was to Israel alone. To them was the kingdom offered that had been promised in the Old Testament.
(Matt. 4:17) "...Repent: for the kingdom of heaven is at hand."
(Matt. 10:5-7) "These twelve Jesus sent forth, and commanded them, saying, Go not into the way of the Gentiles,and into any city of the Samaritans enter ye not:
But go rather to the lost sheep of the house of Israel. And as ye go, preach, saying, The kingdom of heaven is at hand."
So the message and the miracles of Christ verified to Israel that He was the Messiah promised. And many were on the verge of recognizing Him as such. (Matt. 11:23) "And all the people were amazed, and said, Is not this the son of David?" (John 7:31) "And many of the people, believed on him, and said, When Christ cometh, will he do more miracles than these which this man hath done?
This impact upon the people got the attention of the Pharisees and priests. Thus enter 'Judaism'. (John 7:32) "The Pharisees heard that the people murmured such things concerning him;..." And the miracles were so great that they could not be denied by the Pharisees. But at the raising of Lazarus from the dead what was the religious leaders reaction? Just as they were prepared to kill Christ, (Matt. 12:14), so also were they prepared to kill Lazarus. (John 12:9-11) "...But the chief priests consulted that they might put Lazarus also to death....." The religious leaders set about to do whatever they could to take away any reason for the people of Israel to believe that this Christ was the Messiah. Judaism.
So when the people were on the verge of receiving Christ as Messiah, Judaism turned them away. And when Christ healed the demon possessed man by casting the demon out, instead of acknowledging this as from God, the Pharisees said Christ did this by satan instead. (Matt. 12:24,31) Thus the 'unforgiveable sin' was committed. Israel denied her Messiah. Christ now turned away from His offer to Israel concerning the kingdom. They rejected Him. He now rejects them.
Now His road led to the Cross. Individual Jews can be saved, of course. But the house of Israel is under judgement from God.
Good-Ole-Rebel