I. Uzziah's reign in Judah ended with him becoming a leper after arrogantly performing priestly duties. Isaiah then has a vision of God on his throne, surrounded by angels singing "Holy, holy, holy".
II. Upon seeing the holiness and glory of God, Isaiah is overwhelmed by his own sinfulness. However, one of the angels touches Isaiah's lips with a burning coal from the altar, cleansing him from sin.
III. God asks who will go speak for him, and Isaiah volunteers, saying "Here am I; send me". Isaiah recognizes humanity's need for holiness and repents from his sin, opening himself up to be used by God.