Proverbs 27:17-22

Here is the chapter's most famous line, and one of its richest. As one iron blade is honed to an edge by being struck against another, so a man is sharpened — his dull face brightened, his mind quickened, his courage put back on edge — by the face of a friend. God made man for society, not solitude; minds whet each other the way no man can whet himself, for "a man by himself is no man." You can only sharpen souls by souls. This is the verse on which to build a whole doctrine of Christian fellowship: meetings are not evil, shared meals are not evil, warm conversation and kind looks are not evil — they are the very whetstone God provides. The clearest picture of it is the road to Emmaus, two downcast disciples whose hearts burned within them as the risen Christ talked with them by the way (Luke 24:32). Do not try to be a Christian alone; God comforts us, again and again, through the face of a friend — even Paul "was comforted by the coming of Titus" (2 Corinthians 7:6). Find your iron, and let it sharpen you.

Tend the fig tree and you get to eat its figs; serve your master faithfully and you will be honored. Faithful service is never finally wasted — Eliezer running Abraham's house, the diligent servant in the parable. And it rises to the highest Master of all: "if any man serve me, him will my Father honour" (John 12:26). Serve where God has placed you, not as a clock-watcher but as a servant of Christ, and the honor will come.

Look into still water and your own face looks back; look honestly into another man's heart and you find your own. Human nature has not changed since the fall — one corrupt heart is like another, and one renewed heart like another, the whole world over. This is a humbling verse and a useful one. When you are tempted to look down on another man's sin, remember it is your own nature you are reviling — "there, but for the grace of God." And when you feel utterly alone, sure that no one could understand what you carry, this verse answers that too: the heart of man answers to the heart of man; you are not the strange exception you feel like. It is the ground under the golden rule — do unto others, because their hearts are made like yours.

The grave never says "enough" — it swallows generation after generation and yawns for more — and the human eye is exactly like it: never satisfied, always craving the next thing. Give a covetous man a world and he will weep for another. The eye is the avenue of endless wanting, and nothing finite ever fills it. To seek your happiness in this world is to look for the living among the dead. How could an immortal soul ever quench its thirst from anything less than an infinite Source? The eye that is never full on earth is full only when it finally looks on God.

Fire reveals what the metal is made of — and so does praise reveal what a man is made of. Note carefully: praise is a sharper test of a man's character than criticism. Insults a solid man shrugs off; but flattery slips past the guard. If a man is vain and light, praise puffs him up and floats him away; if he is wise and solid, it does not move him a hair. As one old believer warned: Christian, you carry gunpowder about you — when a proud heart meets a flattering tongue, that is a dangerous moment; tell those who carry fire to keep their distance. Watch yourself most carefully not when men curse you, but when they applaud you.

You could pound a fool in a mortar like grain under a pestle and his folly would still not come out of him — because folly has become his second nature, and no amount of outward force can change a nature. This is one of the most important verses in the book about how people really change. Correction, affliction, hard knocks — these by themselves never made one soul good; the belief that suffering automatically works for our saving is a fatal delusion. When Manasseh was finally broken in his Babylonian chains and turned to God, it was not the chains that changed him but the sovereign grace added to them. Religion is, at bottom, a matter of taste — a new appetite for God — and you cannot pound a new taste into a man from the outside. It is the warm south wind of grace, not the battering tempest, that finally gets a man to take off his cloak. (Set this beside chapter 26's dog returning to its vomit: the fool unchanged by the mortar and the dog unchanged by experience teach the same lesson — only a new heart, given by God, changes the nature.)