The Greek compound noun archangelos combines archē (first, chief, ruler) and angelos (messenger, angel), meaning 'chief angel' or 'archangel.' This refers to an angel of the highest rank in the celestial hierarchy. The term appears only twice in the New Testament, both in eschatological contexts.
The archangel appears at two pivotal moments in Scripture: in 1 Thessalonians 4:16, the 'voice of the archangel' accompanies Christ's return and the resurrection of the dead; in Jude 9, Michael the archangel disputes with the devil over the body of Moses. Michael ('Who is like God?') is identified in Daniel 10:13 as 'one of the chief princes' — a guardian of Israel. His authority, however, is entirely derivative: even Michael defers to the Lord in his dispute with Satan, saying 'The Lord rebuke you!' This teaches that no created being — however exalted — operates independently of God's authority.