Paul now compared the body of Christ, the universal church, though by extension the local church as well, to a human body. Again his point was not that the church needs to have unity but that it needs to have diversity.
12:12 The apostle spoke of this comparison in other epistles as well (Rom. 12:4-5; Eph. 4:11-13; Col. 1:18; 2:19). He probably adapted the idea of the body politic, an essentially secular but commonly understood concept, to illustrate the church. There can be unity in a body without uniformity. Here the apostle stressed the fact that diversity among the members is an essential part of a unified body. Evidently the Corinthians were striving for unanimity and did not appreciate that there can and must be diversity in a "spiritual"church.
12:13 The baptism of the Spirit took place initially on the day of Pentecost (Acts 1:5; 2:33; 11:16). Subsequently individual believers experienced Spirit baptism when they personally trusted Christ as their Savior (Acts 11:15-17).
In Spirit baptism the Holy Spirit baptizes (Gr. baptidzo, lit. submerges) the believer into the body of Christ. He makes us a part of it. Water baptism illustrates this. Every believer experiences Spirit baptism regardless of his or her race or social status. We are now on equal footing in the sense that we are all members of the body of Christ.
The figure of drinking of one Spirit recalls John 7:37-39 where Jesus invited the thirsty to come and drink of Him to find refreshment. Baptism and drinking are both initiation experiences and take place at the same time. In the first figure the Spirit places the believer into Christ, and in the second the Spirit comes into the Christian. This is probably a case of Semitic parallelism in which both clauses make essentially the same point.
". . . the Spirit not only surrounds us, but is within us."285
12:14 Both bodies, the physical human body and the spiritual body of Christ, consist of many members. This fact helps us realize our limited contribution to the larger organism. A body composed of only one organ would be a monstrosity.
The modern church often uses this pericope to stress the importance of unity, which is a great need today. However, Paul's emphasis originally was on the importance of diversity.
