In Scripture, girding implies strength: “Thou hast girded me with strength unto the battle” (Psalm 18:39).
We have seen why sincerity is compared to the soldier’s girdle or belt. Now we proceed to the other use of this girdle, which is to strengthen his loins and to fasten his armor close to him. In Scripture, girding implies strength: “Thou hast girded me with strength unto the battle” (Psalm 18: 39). He “weakeneth the strength of the mighty” (Job 12: 21); in this passage the Hebrew meaning is “He loosens their girdle.” It is a grace which establishes and strengthens the Christian in his whole walk; on the contrary, hypocrisy weakens and unsettles the heart: “A double minded man is unstable in all his ways” (James 1: 8).
A soul has as much of heaven’s purity and incorruption as it has sincerity. “Grace be with all them that love our Lord Jesus Christ in sincerity” (Ephesians 6: 24). So, then, the strength of every grace lies in its measure of sincerity. But not only does sincerity cover all infirmities but strengthens the soul for Christian warfare.
“The integrity of the upright shall guide them: but the perverseness of transgressors shall destroy them” (Proverbs 11: 3). Despite all his clever strategies to save himself the hypocrite eventually sinks into his own instability; but sincerity holds the Christian safe above all dangers.
Israel’s hypocrisy was “a generation that set not their heart aright”; they had a spirit which “was not steadfast with God” (Psalm 78: 8). Stones which were not set right on the foundation cannot stand strong nor long.
We see more of this bitter fruit from the hypocrite’s branches in the same Psalm: they “turned back, and dealt unfaithfully… they were turned aside like a deceitful bow” (v. 57). Before a defective bow is bent, you cannot see anything wrong with it. But when you draw the arrow to the head it flies to pieces. This is exactly what happens to a false heart when it is put under stress.
Sincerity, however, keeps the soul pure in the face of temptation. “He that walketh uprightly walketh surely” (Proverbs 10: 9).