The Passion of Christ focused on The Lords physical suffering, when most of his suffering was through sorrow and the Fact the God the Father turned his back on Him because he had taken on the sins of the Word. That is why Jesus cried out, "My God, why hast thou forsaken me.' Hey I apreciate the fact that Jesus suffered and died for me and I believe that He went through a lot of pain, but that fact alone will not win people to Christ. You have to come to repentance. And they made little or no reference to sin and judgement.
People my think by simpathizing with the Lords suffering gets them into the pearly gates. But what did Jesus say about this before he was crucified?
Luke 23:28 And Jesus turned unto them and said,Daughters of Jerusalum, weep not for me, but weep for yourselves, and for your children.
You see Christ has arrose and we no longer need to morn his death, but be sorrowful for all the people who are lost.
You say it don't matter if the people who act out the movie are Christians or not, well the Bible says that a bad tree can't produce good fruit.