1 Corinthians 12:17-20

Think of it this way. If the whole body were just an eyeball, how could it hear sounds? And if the whole body were just an ear, how could it smell different fragrances? But God has carefully designed each member and placed it in the body to function as he desires. A diversity is required, for if the body consisted of one single part, there wouldn’t be a body at all! So now we see that there are many differing parts and functions, but one body.