According to this verse from the book of Proverbs, two things can be done with the truth. It can either be bought or sold. All of us are familiar with buying and selling. Most of us make purchases everyday and even if we are not salespersons, we at least occasionally sell items in a yard sale or flea market.
Men buy and sell in order to make financial gains.
It is only as men know the truth that they will be freed from the guilt and power of sin. The truth about sin must be known. Sin is not some mere inherent weakness or defect. Sin is any lack of conformity to or transgression of God's Law. It is a moral evil for which man is responsible.