Balak (Βαλάκ) is the Greek form of Hebrew Balaq (H1111), meaning "devastator" or "one who lays waste." Balak was the king of Moab who hired Balaam to curse Israel (Numbers 22–24). He appears in the NT once in Revelation 2:14, referenced in the letter to Pergamum.
Balak represents every ruler who tries to use spiritual means to destroy God's people when military means fail. Unable to defeat Israel in battle, Balak hired a prophet to curse them from a spiritual position. God turned every intended curse into a blessing (Numbers 23:11; Deuteronomy 23:5; cf. Romans 8:28). Balak's strategy echoes through history: when the church cannot be destroyed from outside, corruption is introduced from within through false teachers. The church at Pergamum in Revelation 2:14 was warned: Balak's strategy was being replicated in their midst.