08-13-2016, 07:32 PM
The misusage of Jeremiah 31 is a common error of Dispensationalism, used to show some sort of disparity between the nature of the Old Covenant and the New Covenant. However, the writer of Hebrews uses Jeremiah 31 to prove his case in Hebrews 8 that what makes the two covenants different is that there is a new priesthood, which is founded in Christ, after the order of Melchizedek.
Thus, what makes the New Covenant different from the Old Covenant has nothing to do with the former being internalized versus the latter being externalized. In fact, in the Old Covenant, there were saints who already had the law "written in their hearts," like King David. Psalm 40:8 says, "I delight to do Thy will, O my God; yea, Thy law is within my heart." We even see God calling upon Old Covenant Christians who had God's law in their hearts, stating, "Hearken unto Me, ye that know righteousness, the people in whose heart is My law; fear ye not the reproach of men, neither be ye afraid of their revilings."
So, you're totally wrong that the Old Covenant people are different from the New Covenant people because of some internalization of spiritual life in the people of the former. Both covenants had people with the law written in their hearts and minds. The difference is that under the Old Covenant, there was a separate priesthood (Levites) who had the laws of God and whose job was to explain the law to the people of God. In the New Covenant, there is no longer that kind of priesthood because Christ, being the Word, now imparts His word to all covenant people, without the need of a tribal priesthood, and especially, without daily and yearly sacrifices to atone for sins.
So, once again, there is no difference between Old Covenant Christians and New Covenant Christians. They are both in the Father, through Christ, and in the power of the Holy Spirit. The same laws in the Old Testament can be applied to New Testament Christians, through Christ, because Christ is the One Who not only nailed the Law to cross when He died, but resurrected the Law in His resurrection and ascension. But it takes wisdom.