12 For just as the body is one and has many members, and all the members of the body, though many, are one body, so it is with Christ. 13 For by one Spirit we were all baptized into one body--Jews or Greeks, slaves or free--and all were made to drink of one Spirit.
Matthew Henry's Commentary on 1 Corinthians 12:12-13
Commentary on 1 Corinthians 12:12-26
(Read 1 Corinthians 12:12-26)
Christ and his church form one body, as Head and members. Christians become members of this body by baptism. The outward rite is of Divine institution; it is a sign of the new birth, and is called therefore the washing of regeneration, Titus 3:5. But it is by the Spirit, only by the renewing of the Holy Ghost, that we are made members of Christ's body. And by communion with Christ at the Lord's supper, we are strengthened, not by drinking the wine, but by drinking into one Spirit. Each member has its form, place, and use. The meanest makes a part of the body. There must be a distinction of members in the body. So Christ's members have different powers and different places. We should do the duties of our own place, and not murmur, or quarrel with others. All the members of the body are useful and necessary to each other. Nor is there a member of the body of Christ, but may and ought to be useful to fellow-members. As in the natural body of man, the members should be closely united by the strongest bonds of love; the good of the whole should be the object of all. All Christians are dependent one upon another; each is to expect and receive help from the rest. Let us then have more of the spirit of union in our religion.