Discuss among yourselves [emphasis added]:
The holy resentment of Jesus has been made the subject of a famous chapter in Ecco Homo. The contention of this chapter is that he who loves men must needs hate with a burning hatred all that does wrong to human beings, and that, in point of fact, Jesus never wavered in his consistent resentment of the special wrong-doing which he was called upon to witness. The chapter announces as its thesis, indeed, the paradox that true mercy is no less the product of anger than of pity: that what differentiates the divine virtue of mercy from “the vice of insensibility” which is called “tolerance,” is just the under-lying presence of indignation. Thus–so the reasoning runs–“the man who cannot be angry cannot be merciful,” and it was therefore precisely the anger of Christ which proved that the unbounded compassion he manifested to sinners “was really mercy and not mere tolerance.” The analysis is doubtless incomplete; but the suggestion, so far as it goes, is fruitful. Jesus’ anger is not merely the seamy side of his pity; it is the righteous reaction of his moral sense in the presence of evil. But Jesus burned with anger against the wrongs he met with in his journey through human life as truly as he melted with pity at the sight of the world’s misery: and it was out of these two emotions that his actual mercy proceeded.
-B. B. Warfield, “The Emotional Life of Our Lord,” The Person and Work of Christ