It takes a great deal to stir God’s anger, but when it happens, it is holy anger because He is pure and righteous. When the bible tells us that God is “slow to anger” (Nahum 1v3), it means that he is patient beyond man’s capability.
“The LORD is slow to anger but great in power; the LORD will not leave the guilty unpunished. His way is in the whirlwind and the storm, and clouds are the dust of his feet.”
Nahum 1:3 NIV