Romans 8:9-10

Romans 8:9-10. But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his. And if Christ be in you, the body is dead because off sin; but the Spirit is life because of righteousness.

That is why we have aches and pains, and infirmities, because the body is dead; that is, doomed to die, must die; it must see corruption unless the Lord come, and even in that case it must undergo a wondrous change; so we regard our body as dead. No wonder, then, that all those aches and pains and troubles of body do come upon us. The day shall come when, however, even it shall be delivered from the power of death; meanwhile, blessed be God, "the Spirit is life because of righteousness."