The three archangels, who are celebrated by the Catholic Church on September 29, appear at crucial points of the biblical narrative. In the Book of Revelation, Michael leads the heavenly hosts in the battle against evil. Gabriel, who is also known as the Angel of the Annunciation, tells Mary that she is to become of the mother of God. Raphael, who is associated with health and joy, appears to Tobit in the Old Testament, disguised in human form, and cures him of his blindness.