If they were all one part, where would the body be?
As it is, there are many parts, but one body.
References for 1 Corinthians 12:20
The eye cannot say to the hand, “I don’t need you!” And the head cannot say to the feet, “I don’t need you!”
On the contrary, those parts of the body that seem to be weaker are indispensable,
and the parts that we think are less honorable we treat with special honor. And the parts that are unpresentable are treated with special modesty,
while our presentable parts need no special treatment. But God has put the body together, giving greater honor to the parts that lacked it,
so that there should be no division in the body, but that its parts should have equal concern for each other.
If one part suffers, every part suffers with it; if one part is honored, every part rejoices with it.
Now you are the body of Christ, and each one of you is a part of it.
References for 1 Corinthians 12:27
And God has placed in the church first of all apostles, second prophets, third teachers, then miracles, then gifts of healing, of helping, of guidance, and of different kinds of tongues.
References for 1 Corinthians 12:28
Are all apostles? Are all prophets? Are all teachers? Do all work miracles?