The first did not view Ishmael and Isaac, Hagar and Sara, the circumcision and the promise, the old and the new covenant as distinct. They united these dualities within the same covenant of grace that possessed at the same time a physical and spiritual reality, an internal substance and an external administration, and earthly and heavenly blessings. This system was self-consistent, but it could not harmonize itself naturally with biblical data, particularly, the fact that there was not one, but two covenants in Abraham (Gal. 4:24).
