a brief explanation of the words.
First Inquiry. What is truth here? Some by truth understand Christ, who indeed elsewhere is called ‘the truth.’ Yet in this place I conceive it is not properly so understood, because the apostle instanceth in here several pieces and parts of armour, one distinct from another, and Christ cannot so well be said to be a single piece to defend this or that part, as the whole in whom we are complete, compared therefore, Rom. 13:14, to the whole suit of armour, ‘Put ye on the Lord Jesus;’ that is, be clothed and harnessed with Christ as a soldier with his armour cap-à-pie. Some by truth mean truth of doctrine; others will have it truth of heart, sincerity. Those I think right that comprise both; and so I shall handle it. Both indeed are required to make the girdle complete. One will not do without the other. It is possible to find good meanings and a kind of sincerity without, yea against the truth. Many follow an error as they Absalom in the simplicity of their hearts. Such do ill while they mean well. Good intentions do not more make a good action, than a fair mark makes a good shot by an unskilful archer. God did not like Saul’s zeal when he persecuted the Christian church, though he thought, no question, he did him good service therein. Neither is it enough to have the truth on our side, if we have not truth in our hearts. Jehu was a great stickler against idolatry, but kicked down all again by his hypocrisy. Both then are necessary; sincerity to propound a right end, and knowledge of the word of truth to direct us in the right way to that end.
Second Inquiry. What is meant here by loins that are to be girt with this girdle of truth? The loins must be like the girdle. This is spiritual, and therefore they must be so. Peter will help to interpret Paul; ‘Gird up the loins of your mind,’ I Peter 1:13. They are our spirits and minds which must wear this girdle, and very fitly may our spirits and minds be compared to the loins. The loins are the chief seat of bodily strength. Of behemoth it is said, ‘His strength is in his loins,’ Job 40:16. The loins are to the body as carina navi—the keel to the ship. The whole ship is knit to that, and sustained by it. And the body is knit to the loins; if the loins fail, the whole body sinks, hence to ‘smite through the loins’ is a phrase to express destruction and ruin, Deut. 33:11; weak loins and a weak man. If we be but a little weary, nature directs us to lay our hands on our loins to sustain them, as our chief strength. Thus as the actings of our minds and spirits are in their faculties and powers, so we are weak or strong Christians. If the understanding be clear in its apprehensions of truth, and the will sincere, vigorous, and fixed in its purposes for that which is holy and good, then he is a strong Christian; but if the understanding be dark or uncertain in its notions, as a distempered eye that cannot well discern its object—not able to bring its thoughts to an issue, which to close with, and the will be wavering and unsteady, like a needle that trembles between two lodestones—here the man is weak, and all he doth will be so. Feeble spirits cause an intermitting false pulse; so want of strength in the mind to know truth and want of resolution in the will to pursue that which he knows to be holy and good, causeth a man to falter in his course.
The use therefore of these two, FIRST. Truth of doctrine for the mind, and SECOND. Truth of heart or sincerity for the will, is to unite and establish both these facilities. This they do when they are clasped and girt about the soul, as the girdle about the loins of the body. Though the loins be the strength of the body, yet they need an auxiliary to their strength from the girdle to keep those parts close, and unite their force; without which, men, when they would strain themselves, and put forth their strength in any work, find a trembling and looseness in their loins. Hence the ‘shaking of the loins,’ is a phrase to express weakness, Ps. 69:23. Thus our minds and spirits need this girdle to strengthen them in every work we do, or else we shall act nothing vigorously.