Michael is an archangel, one of the principal 50 angels in Christian and Islamic tradition.  He is viewed as the field commander of the Army of God.  He is mentioned by name in the Book of Daniel and the Book of Revelation.  In the book of Daniel, Michael appears as "one of the chief princes" who in Daniel's vision comes to the angel Gabriel's aid in his contest with the angel of Persia (Dobiel), and is also described there as the advocate of Israel and "great prince who stands up for the children of your [Daniel's] people".

In Revelation 12:7-8, "And there was a great battle in heaven, Michael and his angels fought with the dragon, and the dragon and his angels fought back. But he was not strong enough, and they lost their place in heaven."

Much of the late Midrashic detail about Michael was transmitted to Christianity through the Book of Enoch, whence it was taken up and further elaborated. In late medieval Christianity, Michael, together with Saint George, became the patron saint of chivalry, and of the first chivalric order of France, the Order of Saint Michael of 1469. In the British honours system, a chivalric order founded in 1818 is also named for these two saints, the Order of St Michael and St George. St Michael is also considered in many Christian circles as the patron saint of the warrior. Police officers and soldiers, particularly paratroopers, regard him as their patron.

In the War of the Sons of Light Against the Sons of Darkness, Michael is described as the prince of light, leading forces of God against the darkness of evil, who is led by Belial.

The Roman Catholic Church honors Saint Michael with four main titles. He is the Christian angel of death, carrying the souls of all the deceased to heaven, where they are weighed in his perfectly balanced scales (hence Michael is often depicted holding scales). At the hour of death, Michael descends and gives each soul the chance to redeem itself before passing, thus consternating the devil and his minions. St Michael is the special patron of the Chosen People in the Old Testament and is guardian of the Church; it was thus not unusual for the angel to be revered by the military orders of knights during the Middle Ages.  Last, he is the supreme enemy of Satan and the fallen angels.