Why does 1 Corinthians 12 use “body” in both the sense of the entire Body of Christ and then of a local company (12:27)?
In 1 Corinthians 12:12-27, Paul uses the human body as an illustration of how spiritual gifts should function harmoniously for the welfare of an assembly. He points out that bodily members have different abilities, and function in that designed ability to enable the health and welfare of the entire body. As each bodily member has received its ability through divine purpose, so spiritual gifts are also from the same origin. In 12:13, he shows that it was a divine work that formed the entire body of Christ on the Day of Pentecost, when the Spirit descended and every believer was baptized into that body. The baptism of the Spirit seems to be linked specifically with that special day, both in passages that anticipate it and in others, like this, that look back to that unique moment. Individually, we have been brought into the good of that work, and we also have received the Spirit into us upon conversion. The origin of the gifts that every saint possesses lies in the work of the Spirit of God, each member of the body of Christ having some spiritual gift. Consequently, every believer has a niche to fill in that body, and spiritual abilities have been imparted to each one.
In 12:27, Paul is telling us that a local assembly functions like a body in its unified and orderly arrangement and, in doing so, it represents Christ in that locality where it is found. It is not a miniature of the body of Christ, nor is it “the” body of Christ in its entirety (AV), but it is “body of Christ” in character. In so doing, it also represents the entire body of Christ as it functions, through the spiritually gifted believers, to present the reality of that testimony to those around. This truth would impress on our hearts the importance of individual testimony, since that which observers see is not Christ, nor the body of Christ, but the orderly functioning of a local assembly as it bears witness to Christ before others.
The truths of “the body of Christ” and a local assembly as “body of Christ” are distinct, but they are also linked in this way. Local assemblies exist because of the formation of the Body at Pentecost, and spiritual gift necessary to carry on the testimony of a local assembly is derived from the work of the Spirit. A local assembly provides the sphere for the proper function of believers who are also members of the Body of Christ.