1 Corinthians 12:18-21

But now [as things really are], God has placed and arranged the parts in the body, each one of them, just as He willed and saw fit [with the best balance of function]. If they all were a single organ, where would [the rest of] the body be? 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.”