"The penal substitution model has been criticized for depicting a kind Son placating a fierce Father in order to make him love man, which he did not do before. The criticism is, however, inept, for penal substitution is a Trinitarian model, for which the motivational unity of Father and Son is axiomatic. The New Testament presents God’s gift of his Son to die as the supreme expression of his love to men. ‘God so loved the world that he gave his only-begotten Son’ (John 3:16). ‘God is love, . . . Herein is love, not that we love God, but that he loved us, and sent his Son to be the propitiation for our sins’ (I John 4:8-10). ‘God shows his love for us in that while we were yet sinners Christ died for us’ (Rom. 5:8). Similarly, the New Testament presents the Son’s voluntary acceptance of death as the supreme expression of his love to men. ‘He loved me, and gave himself for me’ (Gal. 2:20). ‘Greater love has no man than this, that a man lay down his life for his friends. You are my friends . . .’ (John 15:13f.) And the two loves, the love of Father and Son, are one: a point which the penal substitution model, as used, firmly grasps."
- J.I. Packer from his classic article "What Did the Cross Achieve? The Logic of Penal Substitution."