Unity but not uniformity—that reality must characterize the church of Jesus Christ. In other words, while we must share the same faith, we do not all have to have the same temperament, gifting, or preferences regarding indifferent matters. The first-century Corinthian church had trouble accepting this principle, as some commentators have noted. Their prizing of church leaders with articulate speech over other teachers, for example, showed a desire for uniformity in their leaders—all had to have the same speaking talents (see 1 Cor. 1–2). Similarly, the Corinthian congregation sought uniformity among the laity, elevating tongues as the gift that all should desire, effectively casting different gifts aside (ch. 14).
Certainly, God seeks unity in His church, but He does not call for uniformity. Paul’s use of the human body as a metaphor for the church indicates as much. He begins to employ this analogy in today’s passage, noting that the body is both one and many. Many different members—arms, legs, fingers, ears, and so forth—exist in this body, but there remains an essential unity. The arms may be different and distinguishable from the legs, but the arms and the legs belong to the same body when we are talking about a particular individual. So it is with the church as the body of Christ. The church has many different members, with differences in socioeconomic status, sex, national heritage, and so forth evident among Christians. Nevertheless, we are all united to Christ and are one body (12:12). There is, or should be, unity in faith but diversity in our individual identities and giftings.
This unity is created through our being baptized by one Spirit into the one body of Christ (v. 13). Paul does not mean that water baptism in itself makes one a Christian, yet we should not completely separate water baptism from our incorporation into Christ through regeneration and faith. The New Testament says there is a connection between the two even though the washing with water does not automatically save anyone (see 1 Peter 3:21–22). Furthermore, Paul’s insistence in today’s passage that everyone in Corinth has been baptized in one Spirit argues against the idea that some believers have the indwelling of the Holy Spirit and some do not, as is taught in classic Pentecostalism. The Spirit, in fact, indwells every Christian, and this common indwelling makes us one body.