What does Malachi 3:4 mean?
In several places in Malachi, God indicates that He will no longer accept the offerings of Israel (Malachi 1:10; 2:13). In the case of the priests, this is because they are offering blemished animals (Malachi 1:8). In the case of the people, it is due to their rampant divorce, idolatry, and marrying of non-believers (Malachi 2:11, 14). God goes so far as to say that no worship at all is better than hypocritical, indifferent rituals (Malachi 1:10).Verses 2 and 3 of this chapter explained that God's plan is to "refine" the priests of Israel. Refiners used fire to melt silver and gold; the heat would burn out the undesirable contaminants. In this way, God's judgment will "burn out" the impure and inappropriate from His people, and leave offerings truly worthy of Him. As verse 5 will show, however, this will not merely be limited to the priests, but will also "refine" all of Israel.
Malachi noted, earlier, that there was a time when Israel honored God correctly (Malachi 2:4–5). The problem with the current situation is not that God has broken His promise. In fact, He has changed nothing (Malachi 3:6). What has changed, for the worse, is the attitude of Israel.