In 1 Corinthians 12, Paul notes the beautiful of the church’s diversity, as the Spirit of God gifts each individual believers with particular functions within the greater church.
But then with that as his foundation he moves on in verse 12 to his primary concern in the chapter:
“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.”
In the first eleven verses, Paul used the word “one” to signify individuality and diversity; but now he’s changing the use of that word “one.” Instead of indicating diversity, how is he using that word now? It signifies unity. In other words, Paul wants us to celebrate the functional diversity within the church, but just as important, in fact, considering the amount of attention he now gives to this, perhaps even more important, is the critical recognition of the unity of the church in the midst of the functional diversity. And Paul begin to build a picturesque analogy through the rest of the chapter in order to illustrate the fundamental reality that unifies the functional diversity within the church. What is that analogy? Paul uses the analogy of the human body with its members.
Each member of the human body has an individual function that is different from the other members of the body. The foot can stand; the hand can hold; the eye can see; the ear can hear, and so forth. Each member of the body has specific, individual functions different from other members of the body, but each member is still part of one, unified body.
And so it is with the body of Christ. Each member has been gifted by God with certain functions that are different from other members, but, and this is the point Paul really wants us to get, we are all members of one body. Despite the functional diversity, there is spiritual unity. This is not uniformity, like when you open a box of building blocks where every block is exactly the same shape and size, this is unity along with functional diversity, like when you open a body of Legos full of pieces with different shapes and colors and sizes and functions within the whole.