(Deu 30:6-8 ESV) 6 And the LORD your God will circumcise your heart and the heart of your offspring, so that you will love the LORD your God with all your heart and with all your soul, that you may live. 7 And the LORD your God will put all these curses on your foes and enemies who persecuted you. 8 And you shall again obey the voice of the LORD and keep all his commandments that I command you today.
God says, through Moses, that even after all the curses are suffered by Israel, if they will return to him, he will “circumcise your heart and the heart of your offspring, so that you will love the LORD your God with all your heart and with all your soul, that you may live.”
This is in contrast to —
(Deu 10:12-16 ESV) “And now, Israel, what does the LORD your God require of you, but to fear the LORD your God, to walk in all his ways, to love him, to serve the LORD your God with all your heart and with all your soul, 13 and to keep the commandments and statutes of the LORD, which I am commanding you today for your good? 14 Behold, to the LORD your God belong heaven and the heaven of heavens, the earth with all that is in it. 15 Yet the LORD set his heart in love on your fathers and chose their offspring after them, you above all peoples, as you are this day. 16 Circumcise therefore the foreskin of your heart, and be no longer stubborn.
Before the curses, the Israelites were required to circumcise their own hearts in order to give up their stubbornness and so love God “with all your heart and with all your soul.” But if they fail, and they suffer the curses and yet then return to God, then God will circumcise their hearts for them so that they will love God and “will live.”
I could go through Romans and point out countless allusions to this passage, but these should suffice —
(Rom 2:25-29 ESV) For circumcision indeed is of value if you obey the law, but if you break the law, your circumcision becomes uncircumcision. 26 So, if a man who is uncircumcised keeps the precepts of the law, will not his uncircumcision be regarded as circumcision? 27 Then he who is physically uncircumcised but keeps the law will condemn you who have the written code and circumcision but break the law. 28 For no one is a Jew who is merely one outwardly, nor is circumcision outward and physical. 29 But a Jew is one inwardly, and circumcision is a matter of the heart, by the Spirit, not by the letter. His praise is not from man but from God.
Paul thus declares that his readers are living in the Deu 30 times. The curses are ending and God’s people — a remnant only (ch 11) are returning to God and receiving a circumcision of the heart “by the Spirit” and “not by the letter.” This circumcision, therefore, provides an obedience that cannot come by merely reading and studying a book.
(Rom 7:6 ESV) 6 But now we are released from the law, having died to that which held us captive, so that we serve in the new way of the Spirit and not in the old way of the written code.
This is obviously the same contrast as in 2:29.
(Rom 8:2 ESV) 2 For the law of the Spirit of life has set you free in Christ Jesus from the law of sin and death.
Why “Spirit of life”? Because the promise is that, if you receive the Spirit, “you will live” (Deu 30:6) (the connection of circumcision of the heart with the Spirit is made by the prophets long before Paul).
(Deu 30:9-14 ESV) 9 The LORD your God will make you abundantly prosperous in all the work of your hand, in the fruit of your womb and in the fruit of your cattle and in the fruit of your ground. For the LORD will again take delight in prospering you, as he took delight in your fathers, 10 when you obey the voice of the LORD your God, to keep his commandments and his statutes that are written in this Book of the Law, when you turn to the LORD your God with all your heart and with all your soul.
11 “For this commandment that I command you today is not too hard for you, neither is it far off. 12 It is not in heaven, that you should say, ‘Who will ascend to heaven for us and bring it to us, that we may hear it and do it?’ 13 Neither is it beyond the sea, that you should say, ‘Who will go over the sea for us and bring it to us, that we may hear it and do it?’ 14 But the word is very near you. It is in your mouth and in your heart, so that you can do it.
Paul quotes these last several verses in Rom 10. The point in Deu 30 is that these things can be done. They are not too hard. You don’t have to accomplish great things — travel the seas — to find God’s will or to obey it.
(Rom 10:5-11 ESV) For Moses writes about the righteousness that is based on the law, that the person who does the commandments shall live by them. 6 But the righteousness based on faith says, “Do not say in your heart, ‘Who will ascend into heaven?'” (that is, to bring Christ down) 7 “or ‘Who will descend into the abyss?'” (that is, to bring Christ up from the dead). 8 But what does it say? “The word is near you, in your mouth and in your heart” (that is, the word of faith that we proclaim); 9 because, if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved. 10 For with the heart one believes and is justified, and with the mouth one confesses and is saved. 11 For the Scripture says, “Everyone who believes in him will not be put to shame.”
Paul says that we can obey as Deu 30 requires us to obey by believing in and confessing Jesus. This is what is required to receive the Spirit, but that’s because truly loving God with all your mind and strength requires believing Jesus to be the Messiah. It’s not hard because it’s about faith not works. So says Paul.
So, for the First Century Jews to whom John the Baptist, Jesus, and Peter preached, if they were in the Deu 30 phase of covenant history, what was required to be saved? Therefore, what does “repent” in that particular context mean?
Well, for Peter at Pentecost, faith in Jesus fits very well, but for John the Baptist, Jesus had not yet been revealed. But he did preach —
(Mat 3:2 ESV) 2 “Repent, for the kingdom of heaven is at hand.”
(Mat 3:8-10 ESV) 8 “Bear fruit in keeping with repentance. 9 And do not presume to say to yourselves, ‘We have Abraham as our father,’ for I tell you, God is able from these stones to raise up children for Abraham. 10 Even now the axe is laid to the root of the trees. Every tree therefore that does not bear good fruit is cut down and thrown into the fire.”
(Mat 3:11-12 ESV) “I baptize you with water for repentance, but he who is coming after me is mightier than I, whose sandals I am not worthy to carry. He will baptize you with the Holy Spirit and fire. 12 His winnowing fork is in his hand, and he will clear his threshing floor and gather his wheat into the barn, but the chaff he will burn with unquenchable fire.”
John preached both moral reformation and the Messiah not yet revealed. His reference to winnowing appears to refer to —
(Jer 15:6-8 ESV) 6 You have rejected me, declares the LORD; you keep going backward, so I have stretched out my hand against you and destroyed you — I am weary of relenting. 7 I have winnowed them with a winnowing fork in the gates of the land; I have bereaved them; I have destroyed my people; they did not turn from their ways. 8 I have made their widows more in number than the sand of the seas; I have brought against the mothers of young men a destroyer at noonday; I have made anguish and terror fall upon them suddenly.
The Messiah will come, and just as YHWH allowed his people to be destroyed and scattered, the Messiah will do the same to you — unless you survive the test and are placed in his barn.
John is very deliberately borrowing phrases from the prophets that speak of the destruction of Jerusalem by Nebuchadnezzar. Just as God destroyed his people then, there will soon comes a choice — suffer the same fate or follow the LORD. The choice is to repent or not.
Those who repent will by baptized with the Spirit. Those who do not will remain in Exile and suffer the curses of Exile all over again.