Oh, I did not personally hammer the nails into the cross of Christ, or wield the whip that scourged Jesus Christ, or demand of Pontius Pilate that He be crucified. None of us now living were even born during His Passion and death. But I am every bit as responsible for His death as those that hammered or scourged or jeered or spat at him.
For I (and every single one of us) am guilty of sin. And Scripture is clear: "the wages of sin is death." (Romans 6:23) We humans were barred from heaven because we chose to do evil. We chose death, and faced the consequence of eternal separation from our Creator.
But God loves us infinitely; He wants us to be with Him forever. And to pay the death sentence that by rights we should have suffered, Christ chose to die for us in an incredibly painful, excruciating manner.
This is how He died:
In an act of perfect love, Christ sacrificed Himself to open the gates of heaven and to pay the penalty that was the punishment for our sins. This is the same God who keeps us in existence in a continuous act of creation, without whom we could not exist for even a second. While He kept creatures in being, His creatures were killing Him. We murdered our Maker; He died to save those who killed Him.
Good Friday is the celebration of that unfathomable mystery of God's love, of how a deity who already gave us creatures our very being gave even His life to save His murderers from being punished for their crimes against Him.