He said to Judas, when he betrayed him: 'Friend, wherefore art thou come?'  Just as if he had said: 'Thou hatest me, and art mine enemy, yet I love thee and am thy friend.' . . . As though God in human nature were saying: 'I am pure, simple Goodness, and therefore I cannot will or desire or rejoice in, or do or give anything but goodness.  If I am to reward thee for thy evil and wickedness, I must do it with goodness, for I am and have nothing else.'

Theologica Germanica.