Jeremiah 31:34 - Matthew Poole's English Annotations on the Holy Bible

This must not be so interpreted as if under the gospel there should be no more need of ministerial teaching, for Christ himself sent out his apostles to preach; nor yet as if there should be no more need of brotherly teachings, by instruction or conception; the contrary is commanded, Colossians 3:16. It is only an expression signifying the increase of knowledge, and of the fear of the Lord, that should be after the pouring out of the Spirit: we have such expressions 1 John 2:27. The learned author of our English Annotations thinks this phrase signifies, that under the gospel there should be a greater measure of means of knowledge, and of knowledge got by that means, and of clearness of understanding in persons, or ability to conceive things revealed, and a greater number of persons that should be enlightened with the saving knowledge of God. Others say, that by knowing the Lord is to be understood the first knowledge of God; Christians should not need be taught the first rudiments: but the apostle speaks otherwise, Hebrews 5:12. Others by knowledge understand the fear of the Lord. God saith, they should all know him; but it must not be understood of the same degree and measure, but in a degree of sufficiency for the duties which God expected from them upon their notion and apprehension of God. God makes the root of all this grace to be the free pardon and remission of their sins.