Malachi, the last Old Testament prophet, confronts post-exilic Israel about their spiritual apathy, corrupt worship, and social injustice. Through a series of disputations, God challenges his people's half-hearted devotion and promises the coming of a messenger who will prepare the way for the Lord.
The messenger preparing the way (3:1, fulfilled in John the Baptist); the Sun of Righteousness (4:2); the Lord who suddenly comes to his temple