The prophet Malachi preached to the nation of Judah sometime after 516 BC to a people who had once been exiled for their sin but had now been restored. They had come back from captivity and re-established their nation, restored their capital Jerusalem, and rebuilt their temple.
But Malachi noticed that the same ungodly practices of times past had begun to reappear. Things like a lackadaisical attitude toward worship, lying lips, sinful hearts, and disloyal attitudes. But, according to the prophet there would be a day of reckoning. The messenger of the Lord would come as a refiner of gold and silver, to separate the pure metal from the dross, and to separate righteous from the lost.
(Malachi 3:1-4) 1 “I will send my messenger, who will prepare the way before me. Then suddenly the Lord you are seeking will come to his temple; the messenger of the covenant, whom you desire, will come,” says the Lord Almighty. 2 But who can endure the day of his coming? Who can stand when he appears? For he will be like a refiner’s fire or a launderer’s soap. 3 He will sit as a refiner and purifier of silver; he will purify the Levites and refine them like gold and silver. Then the Lord will have men who will bring offerings in righteousness, 4 and the offerings of Judah and Jerusalem will be acceptable to the Lord, as in days gone by, as in former years.