What is Covenant Theology? God of Promise: Introducing Covenant Theology answers this question. It is Covenant Theology 101. God of Promise is a very readable and helpful introductory work for those who want to have a better understanding of covenant/Reformed theology.
From the cover:
“It’s not just that we were created and then given a covenant,” writes author Michael Horton. “We were created as covenant creatures- partners not in deity but in the drama about to unfold throughout history.” While some Bible readers quake at the mention of “covenant” or “doctrine,” it is vitally important to recognize and understand the significance of covenant and its role in bridging the gap between sinner and salvation. Why? Because to understand covenan theology is to understand how it unifies the diverse teachings of Scripture, binds the Old and New Testaments as one narrative, and enriches the meaning in your relationship with the Triune God. Whether new to Reformed theology or not, every believer needs to understand the importance of covenants. God of Promise unpacks covenant theology so you can explore the core of Christianity: knowing and honoring- the promises of our Creator.”
I also enthusiastically recommend those who desire to understand and live a Gospel-Driven, Christ-centered life, to read this book. “Chapter Nine: New Covenant Obedience” is invaluable in understanding the believer’s relationship to the law and its place in the Christian life under the New Covenant.
Here are a few excerpts:
“If the Sinai covenant is no longer in force and we are “under grace”- that is, under a covenant of promise rather than of law- is any principle of law excluded for the New Testament believer? Do we ignore all ethical teaching in the Old Testament as nonbinding and accept only those commands that we find in the New Testament? What is the place, if any, for the law in the Christian life?..does this new obedience just happen wihtout our needing to follow any prescribed code? Wouldn’t such a view of the law as normative mean a relapse to the killing letter of the law when the Spirit has made us alive in Christ?” pp. 173-174
“A lot of discussion about the role of the law in the new covenant gets off to the wrong start by a failure to make important distinctions. As a result, it is easy for different parties simply to take sides for or against the normative use of the law for Christians.” p. 174
“When we reduce the gospel to forgiveness of sins, we miss out on the “height and depth” of what God has accomplished for us in the new covenant. We can easily ignore, on one hand, the demands that continue to be placed on us and, on the other, the liberating good news that sanctification is not finally up to us. Many Christians confess that justification and forgiveness of sins are by grace alone through faith alone in Christ alone, assuming that this has reference to an initial act. One “gets saved” by grace, but then the Christian life is a matter of stepping in and out of God’s everlasting blessings based on performance. Paul had something like this in mind in Galatians 3:2-3…” p. 186
“God himself did what the law itself could never do. The law commands, but only God can save. This not just good news for the newly converted, but for the mature believer. As John Murray says, ‘The law cannot do any more in sanctification than it did in justification.’ It is no more the office of the law (even according to its third use) to empower us for holiness than to raise us from the dead and put us right before God in the first place. The only source of life and power in the Christian life is the same as it was at the very first: the good news that God has done what the law (and our obedience) could never do.” p. 192
“So the good news is that if you are in Christ (i.e., in union with Christ- J.F.), you are a new creature. The indicative (i.e., the good news of what God has done- “the mercies of God”) drives the imperatives (i.e., the law in its third use). You have not inherited forgiveness and justification by grace only to have your sanctification determined by a covenant of law. The irony is preserved: the law covenant leads to condemnation, while the promise covenant leads to the very obedience that the law requires but could never elicit.” p. 192
“Thus the crucial point in all of this is that even in its third use (guiding rather than condemning), the law can do only what the law does. We must not think that the law drives us to Christ in the beginning (second use) and then Christ drives us back to the law for our acceptance before Godin sanctification (third use). Rather, the law continues to provide us with the soundest guidance available, but apart from Christ and the indicative announcement of what he has done for us and in us, it can only lead us to either despair or self-righteousness. No less than when we first believed, we must always attribute to the gospel the power that fills our sails with gratitude, and to the law the proper course that such gratitude takes. At the beginning, in the middle, and at the end, the gospel is ‘the power of God for salvation to everyone who believes,’ (Rom. 1:16).” p. 194