The Crucifixion is not simply about forgiveness, but about a creation that is profoundly ruined being remade by the power and action of God.
“The Messiah came, not to a purified and enlightened world spiritually prepared for his arrival, but rather to a humanity no nearer to its original goodness than on the day Cain murdered his borther Abel. Indeed, the barbarity of the crucifixion reveals precisely that diagnosis. From beginning to end, the Holy Scriptures testify that the predicament of fallen humanity is so serious, so grave, so irremediable from within, that nothing short of divine intervention can rectify it.”
Fleming Rutledge, The Crucifixion – Understanding The Death Of Jesus Christ Eerdmans, Grand Rapids MI, 2015, pg 127.