Proverbs 23:23 NKJV
Buy the truth, and do not sell it, Also wisdom and instruction and understanding.
Solomon says we should buy understanding. When we buy something we exchange something of value for something else of value. The amount we give is based on the value we place on the item we are getting. We must value understanding to the point we are willing to give a lot to get it. Then that same attitude should help us not give in to the temptation to sell it (the understanding we receive). Sometimes people sell things of value because they want something else, but the thing they are getting in exchange is not nearly as valuable as the item they are selling. Yes, people make foolish decisions. Proverbs 23:23 warns us to evaluate carefully what is luring us, and never sell our understanding for any reason. When we know something, and go contrary to what we know because we are tempted by something that appeals to our flesh, we always end up with regrets. So when we know what to do, we need to bring our flesh under subjection and stay true to the understanding God has given us.