Verses 4-6, the second sentence, set forth the foundation upon which the temperament of unity rests.
There is one body and one Spirit, just as also you were called in one hope of your calling; 5 one Lord, one faith, one baptism, 6 one God and Father of all who is over all and through all and in all.
The groundwork of every building in God’s holy temple is the unity of God; the Trinity, the purpose, and plan.
The church is built on this foundation, and where it has not been, schism and division have risen. Paul instructed his following teachers and pastors to be careful how they build in 1Co 3. They are to build upon Paul’s blueprints as the wise architect and on the foundation which is Christ. If they do, their churches will produce gold, silver, and precious stones, if not, wood, hay, and stubble that is fit to be burned.
The pride of Christians must be removed and humility and meekness take its place. Unfortunately, this hasn’t always happened, and to further complicate the problem, the ecumenical church or visible church has a certain number of non-believers either professing to be Christians, or, not caring to profess, but attending by some familial or societal pressure.
Paul enumerates seven elements: one body, Spirit, hope; one Lord, faith, and baptism, and one God and Father over all. The Lord is at the center of the seven.
This sentence definitely has the structure of a hymn or poem.
There is one body and one Spirit. Every part is of the whole. Without the Spirit the body is lifeless.
Every part of the physical body is part of the whole. Externals, such as clothes, never will be a part of the body. The smallest and most insignificant part of the body, one neuron, a fingernail, etc. is none-the-less part of the whole. Also, once the body loses its spirit, it becomes a lifeless lump of flesh. In the same way, the body of Christ has no insignificant parts, and a part from the Holy Spirit, it has not life. An unbeliever, claiming to be a part of the body, and even acting as a faithful church goer and servant can never be a part of the body for he lacks the Holy Spirit. He is dead in Adam.
Now there are varieties of gifts, but the same Spirit. 5 And there are varieties of ministries, and the same Lord. 6 And there are varieties of effects, but the same God who works all things in all persons. [one Trinity as in EPH 4:4-6] 7 But to each one is given the manifestation of the Spirit for the common good. 8 For to one is given the word of wisdom through the Spirit, and to another the word of knowledge according to the same Spirit; 9 to another faith by the same Spirit, and to another gifts of healing by the one Spirit, 10 and to another the effecting of miracles, and to another prophecy, and to another the distinguishing of spirits, to another various kinds of tongues, and to another the interpretation of tongues. 11 But one and the same Spirit works all these things, distributing to each one individually just as He wills.
Some gifts were temporary to support the building of the infant church: healing, miracles, prophecy, tongues. And yet all, the temporary and the permanent are through the “same” Holy Spirit.
Learning and training are necessary, but do not substitute or neglect the mighty operations of the Holy Spirit in the function of gifts.
12 For even as the body is one and yet has many members, and all the members of the body, though they are many, are one body, so also is Christ. 13 For by one Spirit we were all baptized into one body, whether Jews or Greeks, whether slaves or free, and we were all made to drink of one Spirit. 14 For the body is not one member, but many. 15 If the foot should say, "Because I am not a hand, I am not a part of the body," it is not for this reason any the less a part of the body. 16 And if the ear should say, "Because I am not an eye, I am not a part of the body," it is not for this reason any the less a part of the body. 17 If the whole body were an eye, where would the hearing be? If the whole were hearing, where would the sense of smell be? 18 But now God has placed the members, each one of them, in the body, just as He desired. 19 And if they were all one member, where would the body be? 20 But now there are many members, but one body. 21 And the eye cannot say to the hand, "I have no need of you"; or again the head to the feet, "I have no need of you." 22 On the contrary, it is much truer that the members of the body which seem to be weaker are necessary;
“weaker” - inner organs. We can’t live without them.
Most commentators agree, as do I, that by “weaker” Paul is referring to the inner organs: heart, brain, lungs, etc. This fits the context. The exterior skin or muscle, pierced while no organs or arteries are damaged will heal. The vital organs are much weaker, hence they need musculoskeletal protection, yet they are more vital. The context doesn’t lead us to think that Paul is saying that the hidden spiritual gifts are more vital than the external or more visible gifts. Paul is making the point that we can’t say to any member of the body, “I have no need of you,” anymore than we could say the same to our heart or lungs.
Next, Paul continues his analogy of the physical body with the body of Christ, in that we clothe part of our body, the less honorable, and leave uncovered the honorable.
and those members of the body, which we deem less honorable, on these we bestow more abundant honor [probably - apparel], and our unseemly members come to have more abundant seemliness, 24 whereas our seemly members [i.e. face] have no need of it. But God has so composed the body, giving more abundant honor [apparel] to that member which lacked, 25 that there should be no division in the body, but that the members should have the same care for one another.