Celsus accordingly, as not understanding the doctrine relating to the Spirit of God (“for the natural man receives not the things of the Spirit of God, for they are foolishness unto him; neither can he know them, because they are spiritually discerned”), weaves together (such a web) as pleases himself, imagining that we, in calling God a Spirit, differ in no respect in this particular from the Stoics among the Greeks, who maintain that “God is a Spirit, diffused through all things, and containing all things within Himself.”
Now the superintendence and providence of God does extend through all things, but not in the way that spirit does, according to the Stoics. Providence indeed contains all things that are its objects, and comprehends them all, but not as a containing body includes its contents, because they also are “body,” but as a divine power does it comprehend what it contains. According to the philosophers of the Porch, indeed, who assert that principles are “corporeal,” and who on that account make all things perishable, and who venture even to make the God of all things capable of perishing, the very Word of God, who descends even to the lowest of mankind, would be— did it not appear to them to be too gross an incongruity — nothing else than a “corporeal” spirit; whereas, in our opinion—who endeavour to demonstrate that the rational soul is superior to all “corporeal” nature, and that it is an invisible substance, and incorporeal,— God the Word, by whom all things were made, who came, in order that all things might be made by the Word, not to men only, but to what are deemed the very lowest of things, under the dominion of nature alone, would be no body. The Stoics, then, may consign all things to destruction by fire; we, however, know of no incorporeal substance that is destructible by fire, nor (do we believe) that the soul of man, or the substance of “angels,” or of “thrones,” or dominions, or “principalities,” or “powers,” can be dissolved by fire.
Source: Against Celsus (New Advent)