When we think of wrath, we usually think of vengeance, hardness, rejection, and punishment. A wrathful lamb must be a terrible thing to see. A loving, tender, compassionate God is capable of violent punishment. Isaiah calls divine chastisement God's strange work and act. God prefers to bless but he will avenge the blood of his sainted martyrs.
Mercy can turn to unrelenting condemnation.
There is a soft side and a hard side to the Christian system. He has warm, tender feathers under his pinions, but he also has a rod of iron. It is a mistake to emphasize one aspect of his nature against another appearance of his being. The business of trying to set the Bible against itself is the old story of trying to pit Paul against James. Luther thought the book of James was an epistle of straw because it spoke of works.