Christians understand the Crucifixion of Christ primarily as a salvific act of self-offering on behalf of sinful mankind. As such, it’s easy to understand it primarily as a Sacrifice in which Christ is both Priest and Victim. But that interpretation isn’t comprehensive. Christ was condemned to death as an outlaw and revolutionary. But the charges were false, and Christ was innocent. When asked whether He was a king, Christ answered, “For this was I born and for this did I come into the world: to bear witness to the truth.”
So He was a victim of injustice on account of His message. The connection between salvific self-sacrifice with strong ritual overtones on the one hand and the judicial murder of a truth-teller on the other isn’t obvious. People often liken the death of Socrates to the death of Christ, but Christianity revolves around the Cross in a way post-Socratic philosophy would regard as perverse.
I will attempt to distinguish and correlate the different aspects of the Crucifixion. It’s an incomplete account, but it’s a start. I use the Aristotelian concepts of material, formal, efficient, and final causes:
1.) Material cause: punishment for sin. Christ was sentenced to death as a sinner and outlaw, specifically a blasphemer against the Mosaic Law and a revolutionary against Roman rule. So, Christ–though innocent–was put to death as a sinner. This is fitting, as Christ offered Himself as a vicarious, expiatory offering on behalf of sinners. So Christ died as a scapegoat for sin; He “became sin” by dying a sinner’s death.
2.) Formal cause: martyrdom and regicide. The Scribes and Pharisees condemned Christ because He bore witness to the truth. What truth? The good news of the Kingdom of God, in which Christ Himself exercises royal power in His Father’s Name. That message/rule imperiled the authority of the Scribes and Pharisees, who accused Christ before Pilate. But Pilate, the man who asked, “What is truth?” still wrote, “Jesus of Nazareth, King of the Jews,” on the title above Christ’s Cross. So Christ died as both a martyr (=Prophet) and King.
3.) Efficient cause: self-sacrifice. Christ died willingly as both Priest and Victim. No one took His life from Him unwillingly. The sinners who unjustly put Him to death acted as providential instruments in an act He freely undertook. All sinners have some part in Christ’s death, which is sinful for them. But for Christ, the Crucifixion is a supreme act of charity, and for penitent sinners it is redemption. That is how the shame of the Cross can coexist with its glory. The Victim aspect returns us to the material cause above (#1) insofar as Christ offered Himself as a sin-offering by dying a death proper to sinners.
4.) Final cause: the glory of the merciful Father manifested in the salvation of sinners. Christ offers His self-sacrificial martyrdom to the Father on behalf of sinners so that the Father’s mercy might be manifested in and through the salvation of these sinners. The offering was made *to* the Father (ad Patrem) on behalf of sinners (pro peccatoribus) in order to redeem these sinners and extend the Father’s mercy to them. So we return to the material cause–the sinners who deserved the unjust sentence issued against Christ and who issued that sentence against Him. We also return to the formal cause–the Sacrifice of Calvary effects both the Gospel that Christ preached (for which He died as a Martyr-Prophet) and the Kingdom of God He inaugurated (for which He died as a King).
I don’t know whether I’ve properly assigned the material vs. formal causes, or the formal vs. efficient causes, but there you go.