I submit that we need a clear understanding of the law/gospel contrast, if we want to be healthy in our preaching, churches, families, and individual sanctification. The law/gospel distinction is often misunderstood or overlooked, but it is thoroughly biblical and vital. Consider three different places in Scripture that teach the law/gospel contrast:
Galatians 4:22-26 says, “For it is written that Abraham had two sons, one by a slave woman and one by a free woman. But the son of the slave was born according to the flesh, while the son of the free woman was born through promise. Now this may be interpreted allegorically: these women are two covenants. One is from Mount Sinai, bearing children for slavery; she is Hagar. Now Hagar is Mount Sinai in Arabia; she corresponds to the present Jerusalem, for she is in slavery with her children. But the Jerusalem above is free, and she is our mother.”
These verses contrast the two covenants of law and gospel, which are typologically revealed in Hagar and Sarah. The law covenant is a covenant of slavery to guilt and condemnation. The gospel covenant is a covenant of freedom to life and justification.
Hebrews 12:18-24 says, “For you have not come to what may be touched, a blazing fire and darkness and gloom and a tempest and the sound of a trumpet and a voice whose words made the hearers beg that no further messages be spoken to them. For they could not endure the order that was given, “If even a beast touches the mountain, it shall be stoned.” Indeed, so terrifying was the sight that Moses said, “I tremble with fear.” But you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, and to innumerable angels in festal gathering, and to the assembly of the firstborn who are enrolled in heaven, and to God, the judge of all, and to the spirits of the righteous made perfect, and to Jesus, the mediator of a new covenant, and to the sprinkled blood that speaks a better word than the blood of Abel.”
These verses contrast two mountains: Mount Sinai and Mount Zion. The mountains are types of the law and the gospel. Sinai and Zion were both mountains of the Mosaic covenant. Sinai represents the law that condemns. Zion represents the gospel in the temple, the priesthood, and the sacrifices.
For more on this check out The Founders Journal, Issue 28 – Spring 1997