Revelation 20:9

[That they encompassed the beloved city] obviously does not mean that they gathered or will gather in some one place where, we must suppose, the camp of the saints and the beloved city is to be. For, of course, this city is Christ's church, which is spread over the whole world. Wherever his church will be (and it will be among all nations, "over the breadth of the earth"), there is to be the camp of the saints and the beloved city of God. There will she be, surrounded by all her enemies, intermingled with her as they are and will be in every people, girded with the appalling magnitude of that besetting, hemmed in, straitened and encompassed by the pressures of that mighty affliction; but never will [the church] give up her fighting spirit, her "camp," as John says. [The fire from heaven] must not be taken to indicate that supreme punishment of the ungodly, which is to begin only with the words "Depart from me, accursed ones, into the everlasting fire." For it is then that the wicked are to be cast into fire rather than to have fire fall on them. John's words, "fire from heaven," can well be interpreted as symbolizing the staunchness of the saints, their refusal to give in and do the bidding of their raging enemies. For the heavens are called a "firmament," and by its firmness the ungodly will be tormented by blazing zeal, because [they are] powerless to win over Christ's holy ones to the camp of antichrist. This is the devouring fire, and it is said to come from God because it is by God's grace that the saints are to be unconquerable, to the great torment of their foes.