The Gospel.

Herman Witsius has written:

“Thus Paul says, Rom. x. 14. “how shall they believe in him of whom they have not heard? And how shall they hear without a preacher?” And here indeed both parts of the word are to be made use of; thus the law convincing man of sin, Rom. iii. 20. awakens him to a sense of his misery, drives the sinner out of himself, stirs him up to desire deliverance, and makes him sigh and cry in this manner, “O wretched man that I am, who shall deliver me from this body of death!” Rom. vii. 24. Therefore the law ought certainly to be preached in its full vigour and force, that “knowing the terror of the Lord we may persuade men,” 2 Cor. v. 11. But yet the principal part is performed by the Gospel, which revealing Christ, and the fulness of all grace and salvation in him, allures, by its endearing sweetness, awakened and concerned sinners, to communion with God. Nothing more powerfully sinks into the inmost soul, than that most alluring invitation of Jesus, “Come unto me all ye that labour and are heavy laden, and I will give you rest,” Matt. xi. 28. “Let him that is athirst come, and whosever will, let him take the water of life freely,” Rev. xxii. 16. This is “the power of God unto salvation, to every one that believeth,” Rom. I. 16. If the law only was preached, it would, by its horrors, harden souls, driven to despair, into a hatred of God, as a severe avenger of sin. But by adding the gospel, which makes a bright hope of grace to shine, even on the most abandoned and wretched sinner, if displeased with himself, he heartily desires it: obstinate hearts come to relent, and to be melted down into a love of God, and of his Christ. And therefore nothing ought to be more sweet and dear to us than the most delightful word of the Gospel, in which are brooks of honey and butter, Job xx. 17.”

(Witsius, Herman. The Economy of the Covenants Between God and Man, Volume I, Kingsburg, CA: den Dulk Christian Foundation, 1990, pp. 351.)