In his work Cur Deus Homo? (Why the God-man?), Anselm of Canterbury (1033–1109) sought to answer the question of why the incarnation was necessary. R. C. Sproul writes,

   At the heart of Anselm’s answer to that question was his understanding of the character of God. Anselm saw that the chief reason a God-man was necessary was the justice of God. That may seem to be a strange answer. Thinking of the cross and of Christ’s atonement, we assume that the thing that most strenuously motivated God to send Christ into the world was His love or His mercy. As a result, we tend to overlook the characteristic of God’s nature that makes the atonement absolutely necessary—His justice.
   God is loving, but a major part of what He loves is His own perfect character, with a major aspect being the importance of maintaining justice and righteousness. Though God pardons sinners and makes great provision for expressing His mercy, He will never negotiate His justice. If we fail to understand that, the cross of Christ will be utterly meaningless to us.

—R. C. Sproul, The Truth of the Cross (Reformation Trust, 2007), 18–19.