“Stand therefore, having your loins girt about with truth, and having on the breastplate of righteousness;”
King James Version (KJV)
6:14 Having your loins girt about - That ye may be ready for every motion. With truth - Not only with the truths of the gospel, but with truth in the inward parts; for without this all our knowledge of divine truth will prove but a poor girdle in the evil day. So our Lord is described, #Isa 11:5|. And as a girded man is always ready to go on, so this seems to intimate an obedient heart, a ready will. Our Lord adds to the loins girded, the lights burning, #Lu 12:35|; showing that watching and ready obedience are the inseparable companions of faith and love. And having on the breastplate of righteousness - The righteousness of a spotless purity, in which Christ will present us faultless before God, through the merit of his own blood. With this breastplate our Lord is described, #Isa 59:17|. In the breast is the seat of conscience, which is guarded by righteousness. No armour for the back is mentioned. We are always to face our enemies.
Eph 6:14 Stand therefore, having your loins girt. He next gives the armor that must be worn. The Roman soldier wore a girdle, breast-plate, shoes with iron nails, a helmet to protect his head, and carried a great shield on his left arm which was thrown in front of his body. His weapon was the sword. It was with the sword, not the spear as other nations, that the Romans conquered the world. And these represent parts of the Christian's spiritual armor. Girt about with truth. The girdle kept the armor in place and supported the sword. So truth holds the Christian armor and supports the sword of the Spirit. Having on the breastplate of righteousness. The breast-plate was over the lungs and heart. If Christ's righteousness is over our hearts, they can hardly suffer harm. Compare and see PNT "1Th 5:8".