The Covenant of Grace
The covenant of grace is the Reformed teaching that after the fall God made one saving covenant, administered through every biblical covenant from Genesis 3 to the New Covenant; we gladly agree that salvation has always been by grace through faith in Christ, but the covenants God actually made have different parties and terms and cannot be folded into one.
The lesson walks through the topic one card at a time. The full study is the complete written article, with its sources.
What the Westminster Confession means by one covenant of grace under various administrations
Why covenant theology concludes that there is one people of God in both Testaments
Where we stand together: salvation by grace through faith in every age, on the ground of Christ's death
Why the covenants God made with Noah, Abraham, Israel, David, and the New Covenant cannot be folded into one