Malachi writes approximately 100 years after the people return to Jerusalem. It’s the same old story of God’s faithfulness to his people and their unfaithfulness to him. The people are going through the motions of worshiping God but don’t really want to honor him. The people are about to enter into a time when no more prophecies are written. The next great event will be the birth of Jesus 400 years later.
You are probably tired of hearing God’s repeated warnings and the people’s repeated unwillingness to listen to God. Let’s not be guilty of doing the same thing.