In the former part of this letter the Apostle has been building up a massive fabric of doctrine, which has stood the waste of centuries, and the assaults of enemies, and has been the home of devout souls. He now passes to speak of practice, and he binds the two halves of his letter indissolubly together by that significant 'therefore,' which does not only look back to the thing last said, but to the whole of the preceding portion of the letter. 'What God hath joined together let no man put asunder.' Christian living is inseparably connected with Christian believing. Possibly the error of our forefathers was in cutting faith too much loose from practice, and supposing that an orthodox creed was sufficient, though I think the extent to which they did suppose that has been very much exaggerated. The temptation of this day is precisely the opposite. 'Conduct is three-fourths of life,' says one of our teachers. Yes. But what about the _fourth_ fourth which underlies conduct? Paul's way is the right way. Lay broad and deep the foundations of God's facts revealed to us, and then build upon that the fabric of a noble life. This generation superficially tends to cut practice loose from faith, and so to look for grapes from thorns and figs from thistles. Wrong thinking will not lead to right doing. 'I beseech you, _therefore_, brethren, that ye present your bodies a living sacrifice.' The Apostle, in beginning his practical exhortations, lays as the foundations of them all two companion precepts: one, with which we have to deal, affecting mainly the outward life; its twin sister, which follows in the next verse, affecting mainly the inward life. He who has drunk in the spirit of Paul's doctrinal teaching will present his body a living sacrifice, and be renewed in the spirit of his mind; and thus, outwardly and inwardly, will be approximating to God's ideal, and all specific virtues will be his in germ. Those two precepts lay down the broad outline, and all that follow in the way of specific commandments is but filling in its details. I. We observe that we have here, first, an all-inclusive directory for the outward life.