7 But that He shall come to judgment, the following words teach. “Fire shall go before Him.” Do we fear? Be we changed, and we shall not fear. Let chaff fear the fire: what does it to gold? What you may do is now in your power, so you may not experience, for want of being corrected, that which is to come even against your will. For if we might so bring it about, brethren, that the day of judgment should not come; I think that even then it were not for us to live ill. If the fire of the day of judgment were not to come, and over sinners there impended only separation from the face of God, in whatever affluence of delights they might be, not seeing Him by whom they were created, and separated from that sweetness of His ineffable countenance, in whatever eternity and impunity of sin, they ought to bemoan themselves. But what shall I say, or to whom shall I say? This is a punishment to lovers, not to despisers. They that have begun to feel in any degree the sweetness of wisdom and truth, know what I say, how great a punishment it is to be only separated from the face of God: but they that have not tasted that sweetness, if not yet they yearn for the face of God, let them fear even fire; let punishments terrify those, whom rewards win not. Of no value to you is what God promises, tremble at what He threatens. The sweetness of His presence shall come; you are not changed, you are not awakened, you sigh not, you long not: you embrace your sins and the delights of your flesh, you are heaping stubble to yourself, the fire will come. “Fire shall burn in His presence.” This fire will not be like your hearth-fire, into which nevertheless, if you are compelled to thrust your hand, you will do whatsoever he would have you who does threaten this alternative. If he say to you, “write against the life of your father, write against the lives of your children, for if you do not, I thrust your hand into your fire:” you will do it in order that your hand be not burned, in order that your member be not burned for a time, though it is not to be ever in pain. Your enemy threatens then but so light an evil, and you do evil; God threatens eternal evil, and doest thou not good? To do evil not even menaces should compel you: from doing good not even menaces should deter you. But by the menaces of God, by menaces of everlasting fire, you are dissuaded from evil, invited to good. Wherefore does it grieve you, except because you believe not? Let each one then examine his heart, and see what faith does hold there. If we believe a judgment to come, brethren, let us live well. Now is time of mercy, then will be time of judgment. No one will say, “Call me back to my former years.” Even then men will repent, but will repent in vain: now let there be repentance, while there is fruit of repentance; now let there be applied to the roots of the tree a basket of dung, sorrow of heart, and tears; lest He come and pluck up by the roots. For when He shall have plucked up, then the fire is to be looked for. Now, even if the branches have been broken, they can again be grafted in: then, “every tree which brings not forth good fruit, shall be cut down, and shall be cast into the fire.” “Fire shall burn in His presence.”
8. “And a mighty tempest round about Him”. “A mighty tempest,” in order to winnow so great a floor. In this tempest shall be that winnowing whereby from the saints shall be put away everything impure, from the faithful every unreality; from godly men and them that fear the Word of God, every scorner and every proud man. For now a sort of mixture does lie there, from the rising of the sun unto the going down. Let us see then how He will do that is to come, what He will do with that tempest which “shall be a mighty tempest round about Him.” Doubtless this tempest is to make a sort of separation. It is that separation which they waited not for, who broke the nets, before they came to land. But in this separation there is made a sort of distinction between good men and bad men. There be some that now follow Christ with lightened shoulders without the load of the world's cares, who have not heard in vain, “If you will be perfect, go and sell all that you have, and give to the poor, and you shall have treasure in heaven: and come, follow Me;” to which sort is said, “You shall sit upon twelve thrones, judging the twelve tribes of Israel.” Some then shall be judging with the Lord: but others to be judged, but to be placed on the right hand. For that there will be certain judging with the Lord, we have most evident testimony, which I have but now quoted: “You shall sit upon twelve thrones, judging the twelve tribes of Israel.”...
Source: The Enarrations, or Expositions, on the Psalms (New Advent)