Jeremiah 12:16,17 - Joseph Benson’s Commentary on the Old and New Testaments

If they will diligently learn the ways of my people If they will leave their idolatries, and learn of my people who lived among them to be worshippers of me the true God, and to swear by my name, The Lord liveth That is, pay that homage, which they owe to the Divine Being, to me, the living and true God: as they taught my people to swear by Baal As they drew in my backsliding people to join with them in the service of idols. Then shall they be built in the midst of my people They shall have a portion among my people. The acceptance of the believing Gentiles is here clearly intimated, and their union with the church of God, the middle wall of partition being thrown down. Concerning the actual accomplishment of this prophecy, see Ephesians 2:13-22. But if they will not obey, I will utterly pluck up, &c. But as for those, whether they be Jews or Gentiles, that shall continue in their idolatrous and superstitious practices, or that shall reject the Messiah, and continue in unbelief and disobedience, I will utterly destroy that people. Thus Isaiah 60:12, The nation and kingdom that will not serve thee shall perish: yea, those nations shall be utterly wasted. Those that will not be ruled by the grace of God, shall be ruled by the justice of God. And if disobedient nations shall be destroyed, much more shall disobedient churches, from which better things are expected.