V. 17, 18. _But, my beloved, remember ye the words that were said before by the Apostles of our Lord Jesus Christ, when they said to you that in the last times there should come scoffers who should walk after their own lusts, in a godless state._ This passage shows also clearly, that this epistle is not by St. Jude the Apostle, for he does not count nor reckon himself among the other Apostles, but speaks of them as of those who preached long before him; so that it is reasonable to suppose that another pious man wrote the epistle, one who had read St. Peter's epistles and had drawn this from that source. Who these scoffers are, we have said above: they walk, moreover, after their own lusts,--not merely their fleshly lusts, but those of that godless life which they lead, and they shape all as it pleases them; they care neither for worldly authority, nor the word of God; they are neither under external nor internal government, whether divine or human; they float about between heaven and earth in their lust, just as the devil leads them. V. 19. _These are they who make sects, sensual, who have not the Spirit._ There he has touched on what Peter speaks of, their secretly bringing in of pestilent sects, for these are they that have separated themselves; they divide the unity that is in faith, will not let the ordinary estate of a Christian answer,--namely, that wherein one serves another,--but they set up other estates, and pretend to serve God by these. Besides they are sensual or brutish men, who have no more understanding and spirit than an ox or an ass; they walk according to their natural reason and fleshly mind. They have no God's-word by which they judge themselves, or by which they can live. V. 20, 21. _But, ye beloved, build yourselves up on your most holy faith, through the Holy Spirit, and pray, and keep yourselves in the love of God._ There he defines, in few words, that in which a thoroughly Christian life consists. Faith is laid for the foundation on which we are to build; but to build is to grow from day to day in the knowledge of God and of Jesus Christ, and this takes place through the working of the Holy Spirit. When we are thus built up, we shall do no work to merit anything or to be saved by it, but all to the service of our neighbor. Thus we are to watch, that we abide in love, and not fall from it, like these fools who set up particular works and a peculiar life, and so draw people away from love. _And look for the mercy of our Lord Jesus Christ unto eternal life._ That is the hope, toward which the Holy Cross moves. Therefore should our life be so shaped as to be nothing else than a steady longing and waiting for that life to come; yet so that that waiting be grounded on the mercy of Christ, so that we shall call upon Him with such an understanding as that he is to help us from this to that life out of pure mercy, and not for any work or merit of ours.