In verses 4-11, Paul shows that each person God places in the body receives gifts for the benefit of the entire body. In verses 14-20, he explains that diversity in the body is necessary because, if the entire body was just one part, it could not function. The diversity in this context is in terms of gifts, not doctrine, nationality, sex, or race. Diversity enables the body to be much more effective, efficient, and versatile in performing its intended purpose. Each person has a specific function necessary to the whole.
In verses 21-25, Paul makes a veiled warning that we need to guard against both pride in our abilities and its opposite—equally vain—that we have nothing to give. We become useful members when we choose to set aside these vanities and begin doing what we should.
Verse 18, combined with verses 22-26, teaches us that God Himself has organized the body. We need to understand that the greatest Authority in all of creation has specifically placed us within it and given us gifts. If the body is to function as He has purposed, each part must recognize his individual dependence upon and concern for the whole. In addition, each must understand what the body is designed to accomplish. It is the responsibility of each part to subordinate himself to God to produce the unity that will enable the whole body to do its work.
God expresses these concerns for the body because He wants it to function efficiently and effectively in unity. Therefore, what happens to one part, or what one part does, affects the whole. What we do does indeed make a difference because we are individual parts of a living, spiritual organism. Our actions will produce an increase of good or evil, efficiency or inefficiency in the use of spiritual resources, effectiveness or ineffectiveness of our witness, and growth or backsliding in the grace and the knowledge of Jesus Christ.
