Isaac Watts comments on the progressive revelation of the gospel throughout biblical history: The revelation and discovery of the covenant of grace.
“…the Gospel is a Promise of Salvation from Sin and Hell, by the Death, Righteousness and Grace of our Lord Jesus Christ, to every one that is sincerely willing to accept of it by coming to Christ, or trusting in him; and it includes also the promised Aid of the Holy Spirit to those who seek it, to enable them to receive this Salvation, and to fit them for the final Possession of the promised Glory. It includes also the Revelation of the future Resurrection, the last Judgment and eternal Life. To this End did the Son of God come into the World, that whosoever believes on him should not perish, but have everlasting Life, John iii. 16.”