Malachi prophesied around 450 BC, likely shortly before Nehemiah returned to Jerusalem. He criticized the priests and people of Israel for going through religious rituals without meaning or following God's commands. They offered defective animal sacrifices and questioned God's love while failing to honor him. God reminded them of his covenant with Israel and condemned divorce and marrying foreign wives. Malachi warned that God would come to judge and purify the people, and that Elijah would come before the great day of the Lord to turn people's hearts back to God.