Excerpts from the CNT:

Romans 12:5 indicates that Christ is the element and the sphere of the members in the Body: “So we who are many are one Body in Christ, and individually members one of another.” In the Body of Christ, Christ Himself is the element and sphere of all the members because it is in Christ that we are members one of another.

a. In Him the Many Believers Being One Body

We are one Body in Christ, having an organic union with Him. The phrase in Christ always implies that we are organically united with Christ. This union makes us one in life with Him and with all the other members of His Body. The Body is [3106] not an organization or a society but is altogether an organism produced by the union in life that we have with Christ.

Romans 12 speaks of the Body from the angle of the organic union, that is, from that of the uniting life, a life that unites us together, not only with Christ but with all the other members of Christ. Formerly, we had been born in Adam, but God took us out of Adam and transplanted us into Christ by rebirth. It is rebirth, or regeneration, that has brought us into an organic union with Christ, thus making us a part of Christ. To be organic in the Body means that we must be organically united with Christ and thereby planted into His Body. Then we will have an organic union with the Body of Christ and become a part of the Body.

The Body of Christ is altogether a matter of life and a matter of remaining in our organic union with Christ. When we remain in this organic union, we are in the Body. When we do not remain in this organic union, we are practically and experientially out of the Body. The actuality of the Body is to remain in this organic union with Christ. In order to actually live in the Body life, we must remain in the organic union with Christ. This is simply to remain in Christ. In John 15 the Lord Jesus tells us that He is the vine, we are the branches, and we should abide in Him (vv. 4-5). To abide in Him means to remain in an organic union with Him. When we remain in this organic union with Christ, we are actually living in the Body. But if we do not remain in this organic union, for all practical purposes we have left the Body. For instance, when we speak by ourselves and apart from Christ, we have left the Body. Our gossip, our free talk, and our loose conversation are all signs that we have left the Body.

The Body is not merely a group of Christians coming together. The Body is something that is held together in the organic union with Christ. The Body is altogether a matter in the organic union with Christ. In order to realize the Body of Christ, we need to fully experience the organic union with Christ with a thorough realization that we are organically one with Christ in life. If we do not realize the organic union in Christ, in practicality we are outside of the Body and apart from the Body. [3107]

b. In Him the Believers Being Severally Members One of Another

In ourselves we are not the members of the Body of Christ. If we are in ourselves, in practicality we are not the members of the Body. We are members one of another in Christ—not in ourselves—for Christ is both the element which makes us members one of another and the sphere in which we are members one of another. Hence, we should learn to enjoy Christ as the element and sphere of the members in the Body.