Jer 31:33 – But this shall be the covenant that I will make with the house of Israel; After those days, saith YHVH, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people.
Christian believers are led to understand that somehow God’s law just becomes part of their nature, and so long as they base their actions on ‘love’, they will be pleasing God. Unfortunately, this ‘doctrine’ ignores not only common sense and the personal experience of each believer (don’t we all struggle to know and do the godly thing?), it also ignores accepted scholarly standards of hermeneutics and exegesis, which state that when a term (for ex: law ‘in their hearts’) is defined by the Old Testament, then the OT definition must be applied to the term when it appears in the New Testament.
In other words, the Old Testament defines New Testament terms. 
Modern believers are not taught that the concept of ‘having Torah in one’s heart’ was familiar to Y’shua’s audiences. It is used in the OT scriptures numerous times, and each time it means that one loves Torah and seeks to keep it because of love for YHVH. 
Even worse, believers in the church rarely (actually never) hear Jeremiah’s ‘partner’ verse in Ezekiel:
Ezek 11:19-20 – And I will give them one heart, and I will put a new spirit within you; and I will take the stony heart out of their flesh, and will give them an heart of flesh: That they may walk in my statutes, and keep mine ordinances, and do them:  and they shall be my people, and I will be their God.
The ‘new spirit’ obviously refers to the Holy Spirit and the regeneration of our dead spirits. According to YHVH (God), the purpose of that regeneration is so that we will be able to walk in YHVH’s statutes and keep His ordinances – His Torah – and DO them!!
Shouldn’t we fulfill (πληρόω – plēroō – perform, accomplish, DO) our part of the Refreshed Covenant?  (See Matt 5:17)
© John and Sue Wyatt and The Lamb’s Servant Blog, 2014. Permission to use and/or duplicate original material on The Lamb’s Servant Blog is granted, provided that full and clear credit is given to John and Sue Wyatt and The Lamb’s Servant Blog, with appropriate and specific direction to the original content.
 When Y’shua (Jesus) and the apostles taught, they used “Old Testament” terms, because (1) those terms accurately described Truth; and (2) their listeners and readers were familiar with the definitions of those terms. Scholars have established that when the apostles wrote in Greek, which was not their native language, they used the terms already established by the Septuagint (a Greek translation of the OT written by Jews over 200 years before Y’shua) so that they could be sure that their readers knew what they were talking about. The words and references we read in the NT are all from the OT.
 To ‘have God’s law in one’s heart’ means means that one loves Torah and seeks to keep it because of love for YHVH. See Deut 11:18, Psalm 37:31, Psalm 40:8, Prov 3:1, Ezra 7:10, Job 22:22, Isaiah 51:7, 1 Kings 8:61, etc. When YHVH speaks of ‘giving us a new heart,” He is referring to the change that happens in us when we make our commitment of faith in Y’shua – suddenly we desire ‘with all our hearts’ to learn and do whatever pleases Him. But we do not automatically ‘know’ what pleases Him. Our thoughts are not His thoughts and our ways are not His ways. (Isa 55:8) This is why we are told to ‘work hard to show ourselves acceptable, laborers who need not be ashamed, but who correctly follow the path of the Word of Truth.’ (2Tim 2:15) And of course ‘the Word of Truth’ is the OT, specifically the Torah. This is why the apostle tells us that All [Old Testament] scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: (2Tim 3:16) YHVH expects us to cherish His Word and live by it. There was no ‘New Testament’ when Y’shua walked this earth, yet Y’shua said, It is written, That man shall not live by bread alone, but by every [Old Testament] word of God. (Luke 4:4) My mother and my brethren are these which hear the [Old Testament] word of God, and do it. (Luke 8:21) Yea rather, blessed are they that hear the [Old Testament] word of God, and keep it. (Luke 11:28)
 The words ‘statutes’ and ‘ordinances’ are very specific terms that are quite familiar to readers of the Hebrew Tanakh (“Old” Testament). In no way do the original Hebrew words reflect the Christian understanding of “following the leading of the Holy Spirit.” This Ezekiel passage very specifically refers to the mişwâ/mitzvot (commandments), hōq (statutes), and mišpāţ (regulations) in the Tanakh/Old Testament – it refers to Torah.
 We are accustomed to referring to ‘The New Testament’ when we should actually be referring to ‘The Refreshed Covenant.” A testament is a legal document that remains after a person dies, whereas we have a covenant (an agreement of mutual benefit) with the Living God. Moreover, this covenant is not ‘new.’ In fact, the Greek word translated into English as ‘new’ actually has a more accepted meaning of ‘refreshed.’ In Middle Eastern thought, additional benefits may be added to a covenant, but the original agreement remains in effect as long as the parties live. YHVH made the original covenant with Abraham. We know Abraham still lives because he met with Y’shua on the mount, and of course YHVH still lives. We are told that Y’shua’s disciples are considered to be Abraham’s children (And if ye be Messiah’s, then are ye Abraham’s seed, and heirs according to the promise. Gal 3:29) and that His disciples have been brought into the commonwealth of Israel and the covenants of promise. (Eph 2:12) YHVH promised that He would maintain the covenant with Abraham’s descendants out of loyalty to His “friends”, Abraham, Isaac and Jacob. YHVH is eternal; thus His promises are eternal. His original promise was that He would care for and protect those who obeyed His Torah. With Y’shua’s death and triumphant resurrection, new benefits were added to the covenant – for example, we no longer need to offer sacrifices in the Temple, because Y’shua IS the sacrifice. However, without the covenant (and the Torah included in it), His sacrificial death would be useless – the sacrificial system that we all rely on is Torah-ordained and part of the original covenant! The covenant lives on, and we are blessed to be included in it!