Followers of Christ, according to the Apostles’ Creed, believe in “the holy catholic church.” We do not believe in an institution that is merely human. After all, the Spirit gives birth to the church by granting us faith in Christ (John 3:5). In so doing, the third person of the Trinity fulfills God’s plan to create a people for Himself out of every tribe and tongue (Isa. 19:16–25; 60). Moreover, in forming the church, the Holy Spirit also forms a “communion of saints,” as the creed tells us.
The reality of this communion of saints is defined in question and answer 55 of the Heidelberg Catechism. Today’s passage is one of the texts the catechism uses to explain the nature of this communion, and this verse reveals the foundation of this family. Paul reveals in 1 Corinthians 6:17 that believers are joined so closely to Christ Jesus that we become “one spirit with him.” The idea here is not that we are joined to Jesus in such a way that we lose our identities. Paul is comparing our union with Christ to the one-flesh union that takes place in marriage as part of his critique of illicit sexual relationships in the Corinthian church. In marriage, we retain our individual identities even while we are united as one flesh. A similar thing happens in our union with Christ, although He never conforms to us. Instead, we conform to Him. Actually, our union with Jesus is far deeper than a human marriage, and it produces eternal results. John Calvin comments that Paul speaks of our union with Christ the way he does in 1 Corinthians 6:17 “to show that our connection with Christ is closer than that of a husband and wife, and that the former, accordingly . . . must be maintained with the utmost chastity and fidelity.”
In any case, our union with Christ means that we share in Christ and, consequently, are united to everyone else who is also united to Christ Jesus our Head. There is a deep, eternal fellowship between all those who believe in the Savior. This fellowship even extends past our time, for we worship alongside the saints of all ages (Heb. 12:22–24). As such, our true family is our Christian family, the community with whom we will dwell before God for all eternity.
In the comments Calvin made on today’s passage, the great Reformer noted the importance of maintaining our union with Christ with “the utmost chastity and fidelity.” We must not cheat on our husband, the Lord Jesus Christ, by following after other gods or engaging in impenitent sin. In so doing, we strain our union with Him and, thus, our union with other believers. Let us never do anything to impair the communion we have with Christ and others.