1 Corinthians 12:20-25

But now [as things really are] there are many parts [different limbs and organs], but a single body. The eye cannot say to the hand, “I have no need of you,” nor again the head to the feet, “I have no need of you.” But quite the contrary, the parts of the body that seem to be weaker are [absolutely] necessary; and as for those parts of the body which we consider less honorable, these we treat with greater honor; and our less presentable parts are treated with greater modesty, while our more presentable parts do not require it. But God has combined the [whole] body, giving greater honor to that part which lacks it, so that there would be no division or discord in the body [that is, lack of adaptation of the parts to each other], but that the parts may have the same concern for one another.