The Scope of Union With Christ
Eternity Past
The union of Christ with His people begins before time began. In eternity past, the Father gave Him a people to save from their sins (Eph. 1:3-4). He would perfectly obey the Law on their behalf and take the punishment for their law-breaking upon Himself. What the Lord Christ did, He did not do for Himself, but for His people. He is our covenant head. What He did in fulfilling the Covenant of Redemption, He did for His elect, not for Himself. It is said in Ephesians 1:4 that God “chose us in him before the foundation of the World, that we should be holy and blameless before him”. The sovereign election of God and the plan of redemption was made with Christ as the center of it all. Notice carefully what is said. it is not said that God chose Christ. But it is said that God chose us in Christ.
Christ’s Life, Death, and Resurrection
We were also united with Christ in His life because the life that He lived He lived in our place so as to provide us positive righteousness. The apostle Paul writes, “For as by the one man’s disobedience the many were made sinners, so by the one man’s obedience the many will be made righteous” (Rom. 5:19). This concerns our union with Christ as our covenant head doing for us what we could never do and that is living a perfectly righteous life. In this way, the righteous life which Christ lived is credited to us. He is our righteousness (1 Cor. 1:30; Phil. 3:9). This is the active obedience of Christ (see here).
The New Testament teaches that we were united with Him in His death (Rom. 6:5-6, 8; Gal. 2:20). The curse of the law was removed and the wrath of God satisfied on behalf of the elect. In this sense, Christ’s death becomes our death. We, in Christ, died to sin and the punishment of the law of God. The union of the believer with Christ and Christ with the believer is so intimate that it is said, “our old self was crucified with him” (Rom. 6:6). His crucifixion on our behalf was also our crucifixion.
Scripture likewise teaches that we were united with Him in His glorious resurrection (Col. 2:1, 12). His resurrection is the source of our life and justification (Rom. 4:26). Without the resurrection, there would be no redemption.
Christ’s ascension is His entrance into His throne room, having accomplished everything which the Father had commanded Him to do. He went to heaven and sent us the Holy Spirit Who will apply the work of redemption to the elect. Scripture teaches that we share in the heavenly reign of Christ (Eph. 2:6). Furthermore, Scripture encourages to live as Christ currently lives His resurrection life (Rom. 6:2-11).
Our Lives
The elect were not only united with Christ in His life, death, and resurrection in the past, but they are also, in the present, intimately united with Him through faith. The Scriptures teach that our regeneration and new life is the result of our union with Christ. Paul writes that “even when we were dead in our trespasses, made us alive together with Christ” (Eph. 2:5). A few verses later he also says that we are “created in Christ Jesus for good works” (Eph. 2:10). In 2 Corinthians 5:17, the apostle says, “Therefore, if anyone is in Christ, he is a new creation. The old has passed away; behold, the new has come.” This great blessing of new life is a result of union with Christ.
Our justification by faith has its source in...