God promised through the prophet Jeremiah [31:31, 32] that he himself would make a new covenant with us, not like that covenant which he came to regret with the fathers, when he led them from the land of Egypt. Because they made the covenant void. But this was to be the covenant: “I will put my law in your midst, and I will write my law in your heart and I will be your God and you will be my people.” Because, he will have been propitiated, he might no more remember our iniquities and our sins (Jeremiah 31; Hebrews 8). Likewise, this covenant promised to us knowledge of the true God which also embraces the free forgiveness of sins in Christ and also the he might beget from himself, renewal of man to the image of God.
Caspar Olevianus, De substantia 1.1.1