Origen, on Heb 12:29

“For our God is a consuming fire.”

“Many have produced lengthy discussions of God and God's essence. Some have even said that God has a bodily nature that is composed of fine particles and is like ether. Others have said that God is incorporeal and is of a different essence that transcends bodies in dignity and power. For this reason it is worthwhile for us to see if we have resources from the divine Scriptures to say something about God's essence. In John 4:24 it is stated as if God's essence were spirit, for it says, "God is spirit." But in the law, it is instead as if God's essence were fire, for it is written, "Our God is a consuming fire." In John, however, it is stated as if God were light, for John says, "God is light, and in him is no darkness at all." If, then, we should listen to these words literally, making no inquiry beyond the letter, we would have to say that God is a body.… But because we do not see the consequences if we attribute a body to God when we say, even on the basis of Scripture, that God is some such body as spirit, or consuming fire, or light, unless we accept the conclusions that necessarily follow these assertions, we will disgrace ourselves as foolish and contradicting the obvious. For every fire is subject to extinction because it needs fuel; and every spirit, even if we take the spirit to be simple, because it is a body, admits of change to what is coarser in its own nature. In these matters, then, we must either accept so many absurd and blasphemous things about God in preserving the literal meanings, or, as we also do in many other cases, examine and inquire what can be meant when it is said that God is spirit or fire or light. First we must say that just as when we find it written that God has eyes, eyelids, ears, hands, arms, feet, and even wings, we change what is written into an allegory, despising those who bestow on God a form resembling humans; and we do this with good reason. So also must we act consistently with our practice in the case of the names mentioned above.”

Imported from an open dataset — not yet checked against the printed edition.