"His truth shall be thy shield and buckler." - Psalms 41:4.  

When the adversary heard, by the waters of Jordan, a voice from heaven exclaiming, " This is my beloved Son in whom I am well pleased," he started like one who suddenly discovers a hostile army in the heart of his dominions. Fast he followed him on whom the Lord had lain help, followed him to the wilderness, and rained upon him those missiles by which he had conquered in ten thousand battles. He said to himself no doubt, " Adam was the Son of God and bore the image of God; was I not victorious over him? Who is this that Cometh down from God out of heaven? and what is his armor?" His armor was simply the word of God. This was his shield and buckler; and all the fiery darts of the adversary were hurled in vain. The shield by which Christ came victorious out of his combats with the prince of the power of the air, he took not away with him to heaven, but left for his people. Satan gnashes his teeth when he sees it in the hand of some puny stripling, a candidate for heaven; for it tells him of maddening defeats sustained by him of old. Yes, thou little one, thou hast a buckler of amazing virtue! If the shield of Achilles was sung by Homer, who shall sing the praises of thy shield?

This shield has strange properties. It is only against the adversaries of the Lord that it is of any avail. It is only a follower of Christ that can lift it. It is only while one walks in the appointed path that he can lift it; let him turn to the right hand or the left, and immediately it becomes heavy as iron. What a sad spectacle to see a poor deluded being dragging it after him with all his might. Instead of a shield it is to him a fearful encumbrance. Not there, not there, my friend! Come to the king's highway then will it be to you a shield indeed!