The complaint comes first: 17"You have wearied the LORD with your words." The substance of it is that evil people seem to be doing fine and God apparently does not mind. 17"Where is the God of justice?" It sounds like a question and works like an accusation.
God answers with an announcement: 1"Behold, I send my messenger, and he will prepare the way before me." Then the Lord whom they seek will suddenly come to his temple. This is what the people said they wanted. In the next breath the text turns the promise on the ones who asked: who can endure the day of his coming, and who can stand when he appears? The people wanted vindication against evildoers, and they are promised a visit that will not spare them scrutiny.
The image is a refiner's fire and fullers' soap (verse 2), agents that remove what does not belong. A refiner sits over the metal and watches it (verse 3). The goal is stated: purified priests who bring offerings in righteousness, and worship restored as in the days of old (verses 3-4).
Verse 5 names what the judgment holds people to account for: sorcery, adultery, false swearing, withholding a worker's wages, and oppressing the widow, the fatherless, and the sojourner. The refining is mercy for those it purifies and judgment for what it exposes. The text does not resolve the tension by pretending that one side is not there.
Malachi's audience was asking a question people still ask: if God is just, why is it not obvious? The complaint is a recognizable one. It rarely announces itself as bitterness. It sounds reasonable, even righteous: why do the people cutting corners seem to do fine while faithfulness costs so much and shows so little? It is often dressed as concern for justice when it is impatience with how slowly God works. And the answer leaves no room to stay comfortably on the side of those asking. Who can endure the day of his coming is not a question aimed at someone else. Wanting justice for the people who wronged us means, if applied evenly, that the same justice has plenty to find in the one asking.
The image itself keeps this from despair. A refiner sitting over the fire is someone staying close, controlling how much heat and for how long, because the point is what remains.
The messenger and the Lord are two figures in the verse, and the Gospels give each a face. Malachi's messenger has a name there. John the Baptist is the voice preparing the way (Mark 1:2-4), and Jesus is the Lord who came to his temple and overturned tables in its courts (Matthew 21:12). Malachi could promise a coming refinement only in a picture. The New Testament shows it arriving in a person who went through the fire himself. Because Christ has stood in the fire for everyone hidden in him, the question who can endure no longer has to be answered alone.
Prayer
Father, we confess that we have asked where your justice is while excusing whatever the fire would find in us first. Thank you that the refiner sits close and watches. Thank you that Christ went through the fire himself, so that the purifying we need does not have to consume us. Show us this morning what still needs to be named, and make us people who long for your coming. In Jesus' name, amen.