31 The time is coming, declares the Lord, when I will make a new covenant with the people of Israel and Judah. 32 It won’t be like the covenant I made with their ancestors when I took them by the hand to lead them out of the land of Egypt. They broke that covenant with me even though I was their husband, declares the Lord. 33 No, this is the covenant that I will make with the people of Israel after that time, declares the Lord. I will put my Instructions within them and engrave them on their hearts. I will be their God, and they will be my people. 34 They will no longer need to teach each other to say, “Know the Lord!” because they will all know me, from the least of them to the greatest, declares the Lord; for I will forgive their wrongdoing and never again remember their sins.
The new covenant had to be made because the old covenant did not work. Not even God could legislate morality with the Ten Commandments and the rest of the covenant. The people of Israel still broke the laws repeatedly. In fact, the entire Old Testament is the story of Israel breaking the covenant God made with them with a few brief periods of faithfulness interspersed in between.
Jesus initiated the new covenant, this time written on our hearts and souls rather than stone and paper. Now, with the presence of the Holy Spirit within us as Christians, we can be transformed into the holy people God has called us to be from the inside out. We receive this grace, this transforming grace, every time we offer ourselves to be closer to God. Every time we receive his grace in our lives through true repentance from our sins (repentance that means turning away from the sin, not just feeling sorry about it), we spend time with God in prayer and study of Scripture, we worship with the believing community, and we receive Holy Communion in faith, we grow closer to him and have his new covenant written ever deeper in us.
It is only through this new covenant that we will be saved. The old one did not work. Allow God to write his covenant upon your heart or deepen it through his grace. It is nothing short of miraculous.