"Only Christ can make a shoe fit the Christian's foot so he can easily walk a hard path, because he lines it with the peace of the Gospel.
The peace, which the Gospel brings to the heart makes a saint ready to wade through any trouble that might meet him in his Christian course. And the man who lives in this peace is the only one who stands shod, prepared for every trial. Only Christ can make a shoe fit the Christian's foot so he can easily walk a hard path, because He lines it with the peace of the Gospel. Then even when the way is covered with sharp stones, this shoe goes between the boulders and the foot-- and obstacles are never much felt.
Solomon tells us that the ways of wisdom-- that is, Christ-- "are ways of pleasantness. “But how can this always hold true when we know from experience that some of these paths lead to suffering? Scripture answers: "And all her paths are peace" Proverbs 3:17. Because of peace with God and peace with conscience, the righteous man lacks no pleasure. David, for instance, went to bed satisfied when he had nothing for supper but the gladness God had given his heart. In fact, he promised himself a better night's rest than those full of the world's cheer: "Thou hast put gladness in my heart, more than in the time that their corn and their wine increased. I will both lay me down in peace, and sleep: for thou, Lord, only makes me dwell in safety. Psalm 4:7-8.
The peace which David's conscience enjoyed comforted his body as well: "I laid me down and slept; I awaked, for the Lord sustained me. Psalm 3:5. And David had this sweet rest not only when he lay in the stately palace in Jerusalem but also when he fled for his life from his unnatural son Absalom, and may have lain in the open field. It must have been a good pillow that made him forget personal peril when such a disloyal army hunted him from behind.
This Gospel peace is so transcendent that it causes the believer to lie down and rejoice to sleep in the grave as well as on the softest bed.”Quoted material from, ”The Christian in Complete Armour Daily Readings in Spiritual Warfare” by Gurnall and James S Bell. http://www.moodypublishers.com/pub_productDetail.aspx?id=41823&pid=53617