Read the series so far.
Biblically, a people of God is first of all a people. A people is a nation. A people or nation is (among other things) an ethnic unit, bound together by its solidarity with a common ancestor. These considerations seem beyond serious question.
They also present a problem. In the New Testament, the church is denominated as a people of God. Indeed, the church is often illustrated by referencing Old Testament descriptors that apply to Israel as a people of God (Rom. 9:22-26; Ti. 2:14; 1 Pet.2:9; cf. Ex. 19:5-6; Hos. 2:23). This phenomenon raises two questions. First, how can the church be defined as a people if a people is fundamentally an ethnic unit? Second, how does the church as a people of God stand in relationship to Israel as a people of God, such that descriptions of the one can seemingly be applied directly to the other?
The answer to the first question lies in the church’s unique relationship to Christ. Romans 12:5 declares that church saints are one body “in Christ.” Paul spoke of Andronicus and Junias being “in Christ” before him (Rom. 16:7). He further stated that the Corinthian church was sanctified “in Christ Jesus” (1 Cor. 1:2). Believers who are not yet spiritual are considered to be “infants in Christ” (1 Cor. 3:1). Church saints are new creations “in Christ” (2 Cor. 5:17). Whether Jews, Greeks, slaves, free, male, or female, all church saints are one “in Christ Jesus” (Gal. 3:28). They have now received every spiritual blessing in the heavenlies “in Christ” (Eph. 1:3). They are accepted “in the beloved one,” in whom they have redemption, namely the forgiveness of sins (Col. 1:14). Positionally, they are now seated in the heavenlies “in Christ Jesus” (Eph. 2:6).
The expression in Christ appears to be used rather flexibly in the New Testament. Sometimes it seems to mean by Christ, other times concerning Christ, and still others with reference to Christ. The phrase is far from functioning as a univocal, technical expression. Nevertheless, when it references the church as in the citations above, the expression in Christ is highly theologically significant. It implies that the church stands in some unique relationship to Christ, some relationship that no other saved individuals or peoples share.
The reason is that only the church has been so united to Christ as to constitute His body. Only the church can rightly be called body of Christ. This is the relationship that makes the church unique.
This relationship is defined in 1 Corinthians 12:13, which informs Christians that “we all” have been baptized in or by one Spirit into one body. In context, the one body is clearly the body of Christ, of which every church saint is a member. The “we all” who compose this body include at least Paul and the Corinthians, but likely also Paul’s co-author Sosthenes, as well as his other addressees (“all that in every place call upon the name of Jesus Christ our Lord,” 1 Cor. 1:2). In other words, with reference to church-age believers, 1 Corinthians 12:13 is genuinely universal or catholic in scope.
Equally clearly, the Spirit of 1 Corinthians 12:13 must be the Holy Spirit. In the immediately preceding context, the noun pneuma occurs in the singular no less than nine times. In every one of these occurrences, it transparently refers to the Holy Spirit. It is virtually unthinkable that Paul could suddenly have shifted his usage of the term without giving his readers some clue as to what he was doing. The clear statement of this verse is that all church-age saints are baptized into one body in or by the Holy Spirit.
The question of whether the baptism is in or by the Spirit is really subordinate. A right understanding of the one body does not hinge upon this point. Nevertheless, it is worth pointing out that the immediately preceding context is greatly concerned with the instrumentality and agency of the Holy Spirit. Instrumentality and agency are often distinguished syntactically, but in this context the categories appear to flow together. Four times the instrumentality of the Spirit is designated by the use of the preposition en (twice in 12:2 and twice in 12:9), while in an apparently synonymous parallelism the agency of the Spirit is designated by the use of both dia and kata (12:8). Paul appears to have ransacked the storehouse of Greek prepositions for terms to designate the Spirit’s activity, and his favored preposition was en. Consequently, it is more than likely that 1 Corinthians 12:13 is talking about baptism by the Spirit rather than baptism in the Spirit.
Either way, this baptism is precisely what unites the church saint to Christ’s body. During the present age, every believer becomes a member of the one body of which Christ is head (1 Cor. 12:14-27; Eph. 1:22-23; Col. 1:18). The one body is even identified as Christ Himself (1 Cor. 12:12). For that reason, believers who have been united to the body of Christ are rightly said to be “in Christ.” They are united to the Savior Himself, for He is the head of the body, and the body is His body.
All of the other peoples of God are (or will be) constituted as peoples by their solidarity with a biological ancestor. The church, however, has a different constitution. The church is a people, not because it is united to an ancestor biologically, but because it is united spiritually (i.e., by Spirit baptism) to Christ. Our union with Him is what constitutes us as a people, and it simultaneously constitutes us as a people of God.
In other words, the church is not merely a different people than every other people of God (Israel, Egypt, Assyria, and so forth). The church is actually a different kind of people. All peoples of God have a spiritual dimension, for all peoples of God devote themselves to worshipping the true and living God, who is Spirit. Only the church, however, is spiritual in its very nature and constitution as a people. Only the church is united to Christ, and only the church is presently seated with Christ in the heavenlies.
The spiritual constitution of the church carries significant implications. Since the church is a unique people with a unique nature, inclusion in the church changes the relationship of church saints to the other peoples of the world. That is a large topic, however, and awaits a further discussion.
Death, Like an Overflowing Stream
Isaac Watts (1674–1748)
Death, like an overflowing stream,
Sweeps us away; our life’s a dream,
An empty tale, a morning flow’r,
Cut down and withered in an hour.
Our age to sev’nty years is set;
How short the time! How frail the state
And if to eighty we arrive,
We’d rather sigh and groan than live.
But oh how oft Thy wrath appears,
And cuts off our expected years,
Thy wrath awakes our humble dread:
We fear the power that strikes us dead.
Teach us, Oh Lord, how frail is man;
And kindly lengthen out the span,
Till a wise care of piety
Fit us to die and dwell with Thee.