We come now to the second kind of truth—commended to the Christian under the notion of the soldier’s girdle—and that is, truth of heart. Where it would be known, First. What I mean by truth of heart. Second. Why truth of heart is compared to a girdle.
First. What I mean by truth of heart. By truth of heart, I understand sincerity, so taken in Scripture, ‘Let us draw near with a true heart,’ that is, with a sincere heart, Heb. 10.22. We have them oft conjoined, the one explaining the other: ‘Fear the Lord, and serve him with sincerity and truth,’ Joshua 24:14. We read of ‘the unleavened bread of sincerity and truth,’ I Cor. 5:8. Hypocrisy is a lie with a fair cover over it. An insincere heart is a half heart. The inward frame and motion of the heart comports not with the profession and behaviour of the outward man, like a clock, whose wheels within go not as the hand points without.
Second. Why truth of heart is compared to a girdle. Sincerity, or truth of heart, may fitly be compared to a girdle, in regard of the twofold use and end for which a girdle, especially a soldier’s belt, is worn.
First. The girdle is used as an ornament put on uppermost, to cover the joints of the armour, which would, if seen, cause some uncomeliness. Here—at the loins I mean—those pieces of armour for the defence of the lower parts of the body are fastened to the upper. Now because they cannot be so closely knit and clasped, but there will be some little gaping betwixt piece and piece, therefore they used to put over those parts a broad girdle, that covered all that uncomeliness. Now, sincerity doth the same for the Christian, that the girdle doth for the soldier. The saint’s graces are not so close, nor his life so exact, but in the best there are found infirmities and defects, which are as so many gapings and clefts in his armour, but sincerity covers all, that he is neither put to shame for them, nor exposed to danger by them.
Second. The girdle was used for strength. By this his loins were staid, and united, and the soldier to fight or march. As a garment, the closer it sits, the warmer it is; so the belt, the closer it is girt, the more strength the loins feel. Hence God, threatening to enfeeble and weaken a person or people, saith ‘their loins shall be loosened.’ ‘I will loose the loins of kings,’ Isa. 45:1; and, ‘he weakeneth the strength of the mighty,’ Job 12:21—Heb. ‘he looseth the girdle of the strong.’ Now sincerity may well be compared in this respect to the soldier’s girdle. It is a grace that doth gird the soul with strength, and makes it mighty to do or suffer. Indeed it is the very strength of every grace. So much hypocrisy as is found cleaving to our graces, so much weakness. It is sincere faith, that is the strong faith; sincere love, that is the mighty love. Hypocrisy is to grace as the worm is to the oak—the rust to the iron—it weakens them, because it corrupts them. The metaphor thus opened affords these two doctrinal conclusions, in handling of which I shall comprise what I have to say further of this piece of armour. FIRST. That sincerity or truth of heart in all our ways covers all the Christian’s uncomeliness. SECOND. That truth of heart or sincerity is of excellent use to strengthen the Christian in his whole course.