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. Fire turns all which it seizes into fire. 'Behold how much wood is kindled by how small a fire' (R.V.). The heap of green wood with the sap in it needs but a tiny light pushed into the middle, and soon it is all ablaze, transformed into ruddy brightness, and leaping heavenwards. However heavy, wet, and obstinate may be the fuel, the fire can change it into aspiring and brilliant flame.