8 Therefore, knowing these things, let us use great diligence, while we are in the threshing floor; for it is possible while we are here, to change even out of chaff into wheat, even as on the other hand many from wheat have become chaff. Let us not then be supine, nor be carried about with every wind; neither let us separate ourselves from our brethren, though they seem to be small and mean; forasmuch as the wheat also compared with the chaff is less in measure, but better in nature. Look not therefore to the forms of outward pomp, for they are prepared for the fire, but to this godly humility, so firm and indissoluble, and which cannot be cut, neither is burnt by the fire. It being for their sake that He bears long with the very chaff, that by their intercourse with them they may become better. Therefore judgment is not yet, that we may be all crowned together, that from wickedness many may be converted unto virtue.
Let us tremble then at hearing this parable. For indeed that fire is unquenchable. “And how,” it may be said, “is it unquenchable?” Do you see not this sun ever burning, and never quenched? Did you not behold the bush burning, and not consumed? If then you also desire to escape the flame, lay up alms beforehand, and so you will not even taste of that fire. For if, while here, you will believe what is told you, you shall not so much as see this furnace, after your departure into that region; but if you disbelieve it now, you shall know it there full well by experience, when no sort of escape is possible. Since in truth no entreaty shall avert the punishment from them who have not shown forth an upright life. For believing surely is not enough, since even the devils tremble at God, but for all that they will be punished.
Source: Homilies on the Gospel of St. Matthew (New Advent)