This compound verb means to fight against God—to oppose divine purposes, resist God's work, or battle against deity itself. It combines θεός (God) with μαχέομαι (to fight), creating a term for the ultimate futile warfare. Scribes and Pharisees use it in Acts, warning that opposing the apostles might mean fighting God himself. The word appears in classical texts about mythological battles against the gods. In biblical usage, it suggests the folly and danger of resisting what God is doing, whether from ignorance or willful rebellion.