What does Malachi 3:16 mean?
This verse presents a sudden and interesting change in tone. Those who "feared the LORD" may be some of the same who were just accused of blasphemy (Malachi 3:13–15). They may be a completely separate group of people, who never fell into the sins ascribed to the priests and the people. Either way, even in this season of spiritual darkness, there are those in Israel who are committed to honoring God.This makes verse 16 a tremendous encouragement during times where faithfulness is scarce. God promises, here, to remember the loyalty of those who respond to Him. In context, this is specific to the nation of Israel, but indicates an important aspect of God's character. Whether the people repent and turn back, or stay faithful throughout, God vows to keep a record of their faith. This, more than likely, is exactly the response Malachi—a name literally meaning "My Messenger"—was hoping to get from his prophecy.
Verse 17 will detail how God's remembrance of this repentance, or loyalty, will mean being spared from some of the wrath to come. Verse 18 puts this in terms of a separation between the wicked and the righteous, one made obvious to the world.