God caused division between Abimelech and the Shechemites (see Judg. 9:23) so that they warred against and killed each other. God is not the author of evil, but He does use evil spirits and wicked men to accomplish His divine purposes. Abimelech killed his brothers on a stone (Judg. 9:5), and God used a stone to crush his head (Judg. 9:53; cf. 2 Sam. 11:21). God controls the affairs of mankind and brings justice in the time and manner He determines best.