City of God

The words, “And fire came down out of heaven and devoured them,” are not to be understood of the final punishment which shall be inflicted when it is said, “Depart from me, you cursed, into everlasting fire;” for then they shall be cast into the fire, not fire come down out of heaven upon them. In this place “fire out of heaven” is well understood of the firmness of the saints, wherewith they refuse to yield obedience to those who rage against them. For the firmament is “heaven,” by whose firmness these assailants shall be pained with blazing zeal, for they shall be impotent to draw away the saints to the party of Antichrist.

This is the fire which shall devour them, and this is “from God;” for it is by God's grace the saints become unconquerable, and so torment their enemies. For as in a good sense it is said, “The zeal of Your house has consumed me,” so in a bad sense it is said, “Zeal has possessed the uninstructed people, and now fire shall consume the enemies.” “And now,” that is to say, not the fire of the last judgment. Or if by this fire coming down out of heaven and consuming them, John meant that blow wherewith Christ in His coming is to strike those persecutors of the Church whom He shall then find alive upon earth, when He shall kill Antichrist with the breath of His mouth, then even this is not the last judgment of the wicked; but the last judgment is that which they shall suffer when the bodily resurrection has taken place.