THOMAS: The language of the covenant of redemption emerged in the mid-1640s. I believe it was still somewhat new when the Westminster Assembly met in 1643.
Typically, the notion of the covenant of redemption is pre-temporal. It describes an inter-trinitarian covenant between the Father and the Son to redeem sinners through the substitutionary death of the incarnate Son, the pactum salutis, or the agreement of salvation that was done before creation.
The covenant of grace would be viewed as the enactment of that pre-temporal covenant of redemption in space and time. That covenant of grace is seen in various historical epochs with Adam, Abraham, Moses, David, and the prophetic anticipation of the new covenant or the everlasting covenant in Isaiah, Ezekiel, Jeremiah, and so on.
NICHOLS: If you are new to the Reformed faith and coming out of broader evangelicalism, you are likely entering through the doctrines of grace. You are starting with the sovereignty of God and then moving through the beloved TULIP. I would really encourage you, however, to invest energy in reading about and studying the covenant of grace, moving from just the doctrines of grace as definitive of the Reformed faith to an understanding of the covenant. As you understand that covenant of grace, it will unlock Scripture for you. The covenant of grace is like the puzzle box lid for all the pieces of Scripture that you encounter. It will be so helpful for you.
A great place to start is Jonathan Edwards’ sermons in the History of the Work of Redemption. They are wonderful sermons that lay out this beautiful covenant and relationship, which is not about two separate peoples with distinct futures, Israel and the church, but the one people of God in the covenant of grace. So, I would very much encourage you to embark on that study. It would be very rewarding for you.
THOMAS: We forget that there are lots of people who are reading the Bible for the first time when they become Christians. We usually send them to Mark’s gospel or John’s gospel. Where do you start? If you started in Genesis, you might stop in Leviticus like Gandhi, and there would still be a long way to go.
The more you get to know the Bible, the more you need an answer to something beyond just, “What does John, Paul, or Daniel teach me?” You need an answer to the question, “How do I put the whole Bible together as one narrative, one gospel?” Theologians have answered that question from an understanding that God works through covenants—successive, unfolding, enlarging covenants.
There are only two covenants in space and time. One is the covenant of works with Adam, which he failed. The rest of redemptive history, from the Garden of Eden onwards, is a covenant of grace, which comes in an on-growing trajectory through the history of the patriarchs, Israel, the Babylonian captivity, and the coming of John the Baptist, Jesus, Pentecost, and the growth of the church. Through each successive stage, there is an enlarging of that one covenant of grace.