If the foot would say, "Because I'm not the hand, I'm not part of the body," it is not therefore not part of the body.

If the ear would say, "Because I'm not the eye, I'm not part of the body," it's not therefore not part of the body.

For we know in part, and we prophesy in part;

whereas our presentable parts have no such need. But God composed the body together, giving more abundant honor to the inferior part,