One of the key differences between the Covenant Theology of the framers of the 1689 London Baptist Confession of Faith and that of the Westminster Confession has to do with the nature of the Covenant of Grace, that is, the covenant through which sinners are saved. The Westminster Confession presents the view of one over-arching Covenant manifested in several historical covenants (e.g. Abrahamic, Mosaic, New). The 1689 Confession, on the other hand, maintains that prior to the formal establishment of the New Covenant at the time of Christ, the “covenant of grace” consisted only in the form of gospel promises revealed “by farther steps” throughout biblical history. If an individual living before Christ believed these promises, he was redeemed by the future spilled blood of Christ just as surely as believers living today.
Nehemiah Coxe answers the question, Was there an old covenant administration of the covenant of grace?.