An important foundation stone for postmillennialism is the idea of “covenant.” Paul subsumes all the Old Testament covenants under one principle: gracious promise. When he writes to the Gentile Christians, he urges them to “remember that at that time you were… foreigners to the covenants of the promise, without hope and without God in the world” (Eph. 2:12). Although there were “covenants” plural, they all developed “the promise” singular.
Old Testament Foundation
A key manifestation of the Covenant of Grace in the Old Testament, a fundamentally significant covenant “of promise,” is found in the Abrahamic Covenant. First recorded in Genesis 12, the Abrahamic Covenant continues the creational principle of universal glory to God and the redemptive power of God in history: “I will make you into a great nation and I will bless you; I will make your name great, and you will be a blessing. I will bless those who bless you, and whoever curses you I will curse; and all peoples on earth will be blessed through you” (Gen 12:2-3). This important covenant is alluded to a great number of times in the New Testament.
It is crucial to recognize the universal scope of blessing established in this covenant: “all peoples on earth will be blessed through you.” Because of this glorious promise, Paul writes in Romans 4:13: “It was not through law that Abraham and his offspring received the promise that he would be heir of the world, but through the righteousness that comes by faith.” Through the establishment of His covenant by the glorious labor of His Son, Who is the ultimate Abrahamic Seed, God intends to spread redemption throughout the “world” and upon “all peoples on earth.”
The covenantal promise of God’s blessings overwhelming “all peoples on earth” is founded on the very being of God. His covenant power is exemplified in His covenant name: Jehovah. That name, according to Exodus 3:14 means: “I Am that I Am.” This self-designation is particularly important to our understanding of God and of His covenant. This statement is found in the imperfect tense in Hebrew, thereby distinguishing a constantly manifested quality. From this name we may discern certain of God’s intrinsic qualities: (1) His aseity. God exists of Himself. He is wholly uncreated and self-existent. There is no principle or fact back of God accounting for His existence. (2) His eternity. He is of unlimited, eternal duration. The combination of the verb tense (imperfect) and its repetition (“I am” / “I am”) emphasize His uninterrupted, continuous existence. (3) His sovereignty. He is absolutely self-determinative. He determines from within His own being. As the Absolute One, He operates with unfettered liberty. He is not conditioned by outward circumstance. He is what He is because He is what He is. He is completely self-definitional and has no need of anything outside of Himself. This is the God Who makes covenant. This is the covenant God Who establishes certain hope in the place of wishful thinking.
This covenantal victory was confirmed in Old Testament prophecy, where we read of the Abrahamic Covenant: “Your descendants will take possession of the gates of their enemies” (Gen. 22:17b). The gate of an ancient city was the place where special defenses were placed (Deut. 3:5; 28:52) and where justice was administered (Deut. 16:18; 17:5ff). The Abrahamic Covenant promises the conquest of all opposition.
New Covenant Expectation
This promise of victory comes over into the New Testament in Jesus’ statement to Peter: “On this rock I will build my church, and the gates of hell will not prevail against it” (Matt. 16:18). The defense and injustice of Satan’s walled city, his kingdom, will succumb to the onslaught of Christ’s Church. This is covenantal promise. It is the clear testimony of the covenantal Scripture that Christ came for the express purpose of defeating Satan and supplanting his nefarious kingdom: “The reason the Son of God appeared was to destroy the devil’s work” (1 John 3:8b). He appeared in history to destroy Satan in history. “Since the children have flesh and blood, he too shared in their humanity so that by his death he might destroy him who holds the power of death—that is, the devil” (Heb. 2:14). He came in historical form so that He might win historical victory.
The New Covenant development of the Abrahamic Covenant promises an unshakable kingdom: The writer of Hebrews writes to first century Christians: You have come “to Jesus the mediator of a new covenant, and to the sprinkled blood that speaks a better word than the blood of Abel. See to it that you do not refuse him who speaks. If they did not escape when they refused him who warned them on earth, how much less will we, if we turn away from him who warns us from heaven? At that time his voice shook the earth, but now he has promised, ‘Once more I will shake not only the earth but also the heavens.’ The words ‘once more’ indicate the removing of what can be shaken—that is, created things—so that what cannot be shaken may remain. Therefore, since we are receiving a kingdom that cannot be shaken, let us be thankful, and so worship God acceptably with reverence and awe, for our ‘God is a consuming fire’” (Heb. 12:24-29).
The covenantal promise of God involves the blessing of all the peoples of the earth, the overcoming of historical opposition to the people of God, and the establishment of the unshakable purpose of God.