(1.) The gospel shall work good upon those that are disposed to be good, to them it shall be a savour of life unto life (v. 3): He shall sit as a refiner. Christ by his gospel shall purify and reform his church, and by his Spirit working with it shall regenerate and cleanse particular souls; for to this end he gave himself for the church, that he might sanctify and cleanse it with the washing of water by the word (Eph. v. 26) and purify to himself a peculiar people, Tit. ii. 14. Christ is the great refiner. Observe, [1.] Who they are that he will purify—the sons of Levi, all those that are devoted to his praise and employed in his service, as the tribe of Levi was, and whom he designs to make unto our God spiritual priests (Rev. i. 6), a holy priesthood, 1 Pet. ii. 5. Note, All true Christians are sons of Levi, set apart for God, to do the service of his sanctuary, and to war the good warfare. [2.] How he will purify them; he will purge them as gold and silver, that is, he will sanctify them inwardly; he will not only wash away the spots they have contracted from without, but will take away the dross that is found in them; he will separate from them their indwelling corruptions, which rendered their faculties worthless and useless, and so make them like gold refined, both valuable and serviceable. He will purge them with fire, as gold and silver are purged, for he baptizes with the Holy Ghost and with fire (Matt. iii. 11), with the Holy Ghost working like fire. He will purge them by afflictions and manifold temptations, that the trial of their faith may be found to praise and honour, 1 Pet. i. 6, 7. He will purge them so as to make them a precious people to himself. [3.] What will be the effect of it: That they may offer unto the Lord an offering in righteousness, that is, that they may be in sincerity converted to God and consecrated to his praise (hence we read of the offering up, or sacrificing, of the Gentiles to God, when they were sanctified by the holy Ghost, Rom. xv. 16), and that they may in a spiritual manner worship God according to his will, may offer the sacrifices of righteousness, (Ps. iv. 5), the offering of prayer, and praise, and holy love, that they may be the true worshippers, who worship the Father in spirit and in truth, John iv. 23, 24. Note, We cannot offer unto the Lord any right performances in religion unless our persons be justified and sanctified. Till we ourselves be refined and purified by the grace of God, we cannot do any thing that will redound to the glory of God. God had respect to Abel first, and then to his offering; and therefore God purges his people, that they may offer their offerings to him in righteousness, Zeph. iii. 9. He makes the tree good that the fruit may be good. And then it follows (v. 4), The offering of Judah and Jerusalem shall be pleasant unto the Lord. It shall no longer be offensive, as it has been, when, in the former days, they worshipped other gods with the God of Israel, or when, in the present days, they brought the torn, and the lame, and the sick, for sacrifice; but it shall be acceptable; he will be pleased with the offerers, and their offerings, as in the days of old and as in former years, as in the primitive times of the church, as when God had respect to Abel's sacrifice and smelled a savour of rest from Noah's, and when he kindled Aaron's sacrifice with fire from heaven. When the Messiah comes, First, He will, by his grace in them, make them acceptable; when he has purified and refined them, then they shall offer such sacrifices as God requires and will accept. Secondly, He will, by his intercession for them, make them accepted; he will recommend them and their performances to God, so that their prayers, being perfumed with the incense of his intercession, shall be pleasant unto the Lord; for he has made us accepted in the Beloved, and in him is well pleased with those that are in him (Matt. iii. 17) and bring forth fruit in him.