D.A. Carson, contributing in The Supremacy of Christ in a Postmodern World, gives this stirring reminder of the ultimate reason behind Jesus going to the cross to die for our sins:
Jesus came to complete the work that his Father gave him to do (John 17:4). We so often think that the ultimate motivation behind the cross is God’s love for us. I do not want to downplay the importance of that love…But we must see that in John’s Gospel the motivating power behind the entire plan of redemption was the Father’s love for his Son and the Son’s love for his Father. When Jesus found himself in an agony in Gethsemane, he did not finally resolve to go through with the plan of redemption by saying, “This is awful, but I love these sinners so much I’ll go to the cross for them” (though in a sense he might have said that), but “Not my will but yours be done.” In other words, the dominating motive that drove him onward to perfect obedience was his resolution, out of love for his Father, to be at one with the Father’s will. Though we poor sinners are the unfathomably rich beneficiaries of God’s plan of redemption, we are not at the center of everything. At the center was the love of the Father for the Son and the love of the Son for the Father.