From a reader:

The purpose of the Passion is most definitely to reignite the notion of collective guilt. However, the collective group responsible is a lot bigger than the Jews or the Romans. It is all of us. John 3:16 says that God loved the world enough to give His Son for it. Romans 5:6 says that just at the right time while all of us were completely powerless to save ourselves Christ died for the ungodly. If the Passion assists in reigniting the notion that each and every one of us individually and collectively was sufficient cause and reason for the suffering and death of Christ, then it has done its job.