This has been stirring in me in a slightly different emphasis. People are missing the point when they try to soft-peddle the Jews' role in Christ's death. In fact, Jesus Himself said theirs was the greater sin, for handing Him over. HOWEVER, Jesus forgave them and by His teaching prior to the Cross, and at the Cross, He taught us to do the same. The Romans were culpable as, indeed, they were "the help," since the Jews could no longer execute people for offenses against the state, being in Roman subjection. But if neither the Jews nor the Romans had acted, Jesus would not have suffered the fate the Father prepared for Him from before the foundation of the world and no one would be saved.
We can thank the Jews and the Romans for what they did in our stead, for in handing over the Son of God to crucifixion and death, they enabled the resurrection, and redemption for anyone who hungers for it.