My dad told me something I thought was strange. He saw me sawing on a nylon rope with my pocketknife, and said, “You know, a dull knife will cut you.” That made no sense at the time, but a while later I learned he was right. While trying to force that dull blade through a piece of wood, the blade slipped and jabbed my hand.
So, why is a dull knife dangerous? Because it requires more pressure to cut, which increases the likelihood that the knife will slip with great force behind it, cutting or stabbing whatever it crosses.
Not only will a dull knife cut you—another paradox—only something hard, like stone or steel, can make it sharp. The knife blade is sharpened by friction on a piece of stone or steel. The pressure and abrasion of the stone on the blade sharpens the knife.
God used this fact to teach the principle: “Iron sharpens iron, so one man sharpens another” (Proverbs 27:17). So, what can we learn? Three things:
First, people around you will exert influence for better or worse—they can make you sharp or dull.
“He who walks with wise men will be wise, but the companion of fools will suffer harm” (Proverbs 13:20). Your friends affect you. Your companions influence your attitude, behavior, language, and values. Surround yourself with people who bring out the best in you.
Second, to make a knife sharp requires abrasive resistance, pressure, friction, and even a little heat. So it is with you. To knock off your rough, dull edges, rendering you sharp and useful requires friends who are honest, loving and truthful. Like “iron on iron,” you need people who will expose your hypocrisy, correct your poor habits, confront your laziness and challenge your thinking. It may not be comfortable getting sharpened, but the results are worth it.
Third, just as friends can sharpen you, others may dull you, rendering you less effective. Some companions will soil your testimony and tempt you to do the wrong thing. These are ones you need to avoid like the plague. “Do not be deceived: Bad company corrupts good morals” (1 Corinthians 15:33). For these reasons every believer needs to be active in a local church. We are changed for the better by regular exposure to godly mentors.
A dull knife will cut you but a sharp one can bless you. Surround yourself with people who improve you, so you can in turn sharpen others.