Then, with a sudden and striking change of metaphor, the prophet passes from a picture of the extreme of fierceness to one of the extreme of tenderness. 'As birds flying'—mother birds fluttering over their nests—'so will the Lord of hosts defend Jerusalem,' hovering over it and going from side to side to defend with His broad pinions, 'passing over, He will preserve it.' These figures are next translated into the plain promise of utter discomfiture and destruction, panic and flight as the portion of the enemies of Israel, and the whole has this broad seal set to it, that He who promises is 'the Lord, whose fire is in Zion, and His furnace in Jerusalem.'

We shall not understand these great words if we regard them as only a revelation of destructive and terrible power. They are that indeed, but they are far more than that. It is the very beauty and completeness of this emblem that has a double aspect, and is no less rich in joy and blessing than pregnant with warning and terror. As Isaiah says in another place, Jerusalem is 'Ariel,' which probably means 'the hearth of God.' His presence in the city is as a fire for the comfort and defence of the happy inhabitants, and at the same time for the destruction of all evil and enemies. Far more truly than He dwelt in the city of David does God dwell in the Church, and His presence is its security. What, then, of instruction and hope may we gather from this wonderful emblem?

I. In the Church, God is present as a great reservoir of fervid love.

Every language has taken fire as the symbol of love and emotion. We speak so naturally of warm love, fervent feeling, glowing earnestness, ardent enthusiasm and the like, that we are scarcely aware of using figurative language. We do not usually ascribe emotion to God, but surely the deepest and most sacred of the senses in which it is true that fire is His emblem, is that He is love. His fire is in Zion. He dwells in His Church, a storehouse of blazing love, heated seventy times seven hotter than any creatural love, and pouring out its ardours for the quickening and gladdening of all who walk in the light of that fire, and thaw their coldness at its blaze.

Then, if so, how comes it that so many Christian Churches are ice-houses instead of furnaces? How comes it that they who profess to live in the Zion where this fire flames are themselves so cold? If God's blazing furnace is in Jerusalem, it should send the thermometer up in all the houses of the city. But what a strange contradiction it is for men to be in God's Church, the very focus and centre of His burning love, and themselves to be almost down below zero in their temperature! The Christian Church ought to be all aflame in all its members, with the fire of love kindled and alight from God Himself. Every community of Christian people ought to radiate warmth and light which it has absorbed from its present God. Our love ought to answer His, and, being caught and kindled from that mighty fire, should throw back to its source some of the heat received, in fervours of reflected love, and should pour the rest beneficently on all around. Love to God and love to man are regarded in Christian morals as beams of the same fire, only travelling in different directions. But what a miserable contrast to such an ideal the reality in so many of our churches is! A fiery furnace with its doors hung with icicles is no greater a contradiction and anomaly than a Christian Church or a single soul, which professes to have been touched by the infinite loving kindness of God, and yet lives as cold and unmoved as we do. The 'Lord's fire is in Zion.' Are there any tokens of that fire amongst us, in our own hearts and in our collective temperature as Christian Churches?

There is no religion worth calling so which has not warmth in it. We hear a great deal from people against whom I do not wish to say a word, about the danger of an 'emotional Christianity.' Agreed, if by that they mean a Christianity which has no foundation for its emotion in principle and intelligence; but not agreed if they mean to recommend a Christianity which professes to accept truths that might kindle a soul beneath the ribs of death and make the dumb sing, and yet is never moved one hair's-breadth from its quiet phlegmaticism. There is no religion without emotion. Of course it must be intelligent emotion, built upon the acceptance of divine truth, and regulated and guided by that, and so consolidated into principle, and it must be emotion which works for its living, and impels to Christian conduct. These two provisoes being attended to, then we can safely say that warmth is the test of life, and the readings of the thermometer, which measure the fervour, measure also the reality of our religion. A cold Christian is a contradiction in terms. If the adjective is certainly applicable, I am afraid the applicability of the noun is extremely doubtful. If there is no fire, what is there? Cold is death.

We want no flimsy, transitory, noisy, ignorant, hysterical agitation. Smoke is not fire. If the temperature were higher, and the fire more wisely fed, there would not be any. But we do want a more obvious and powerful effect of their solemn, glorious, and heart-melting beliefs on the affections and emotions of professing Christians, and that they may be more mightily moved by love, to all heroisms and service and enthusiasms and to consecration which shall in some measure answer to the glowing heart of that fire of God which flames in Zion.

II. God's revelation of Himself, and presence in His Church, are an instrument of cleansing.

Fire purifies. In our great cities now there are 'disinfecting ovens,' where infected articles are taken, and exposed to a high temperature which kills the germs of disease, so that tainted things come out sweet and clean. That is what God's furnace in Zion is meant to do for us. The true way of purifying is by fire. To purify by water, as John the Baptist saw and said, is but a poor, cold way of getting outward cleanliness. Water cleanses the surface, and becomes dirty in the process. Fire cleanses within and throughout, and is not tainted thereby. You plunge some foul thing into the flame, and, as you look, the specks and spots melt out of it. Raise the temperature, and you kill the poison germs. That is the way that God cleanses His people; not by external application, but by getting up the heat. The fire of His love, the fire of His spirit, is, as St. Bernard says, a blessed fire, which 'consumes indeed, but does not hurt; which sweetly burns and blessedly lays waste, and so puts forth the force and fire against our vices, as to display the operation of the anointing oil upon our souls.' The Hebrew captives were flung into the fiery furnace. What did it burn? Only their bonds. They themselves lived and rejoiced in the intense heat. So, if we have any real possession of the divine flame, it will burn off our wrists the bands and chains of our old vices, and we shall stand pure and clean, emancipated by the fire which will consume only our sins, and be for our true selves as our native home, where we walk at liberty and expatiate in the genial warmth. That is the blessed and effectual way of purifying, which slays only the death that we carry about with us in our sin, and makes us the more truly living for its death. Cleansing is only possible if we are immersed in the Holy Ghost and in fire, as some piece of foul clay, plunged into the furnace, has all the stains melted out of it. For all sinful souls seeking after cleansing, and finding that the 'damned spot' will not 'out' for all their washing, it is surely good news and tidings of great joy that the Lord has His fire in Zion, and that its purifying power will burn out all their sin.

III. Further, there is suggested another thought: that God, in His great revelation of Himself, by which He dwells in His Church, is a power of transformation.