The mind is flexible and can keep changing. To a large extent, any such changes will be determined by what we allow into our mind and what we choose to dwell on. By dwelling or meditating on Jehovah’s way of thinking, we can prove to ourselves that his viewpoints are right. It will then be our natural desire to bring our thoughts into alignment with his. Note, however, that in order to make our mind over to Jehovah’s way of thinking, we need to “stop being molded by this system.” We must stop taking into our minds ideas or viewpoints that are in opposition to God’s. The importance of this preliminary step can be illustrated with food. A person might seek to improve his health by eating food that is nutritious. But of what value would that be if he is also ingesting regular doses of contaminated food? Similarly, feeding on Jehovah’s thoughts will be of limited value if we are corrupting our mind with worldly ideas. w18.11 4:14-15

We must be firmly resolved to live in harmony with the truth day by day. Wear the belt of truth around your waist. In Bible times, the belt of a soldier supported and protected his waist and his internal organs. For his belt to provide protection, however, it had to be tight. A loose belt gave little support. How does our spiritual belt of truth protect us? If we keep it wrapped tightly around us like a belt, the truth will guard us from faulty reasoning and will help us to make sound decisions. When we are tempted or under trial, Bible truth will strengthen our resolve to do what is right. Just as a soldier would never have thought of going into battle without his belt, we must be determined never to loosen or remove our belt of truth. Rather, we do all we can to keep it tight around our body by living in harmony with the truth. w18.11 2:15

We do not find the truth in God’s Word without effort. We must be willing to make whatever sacrifices are needed to obtain it. As the wise writer of Proverbs notes, once we “buy,” or acquire, “truth,” we must be careful not to “sell,” or lose, it. Even something that is free may come at a cost. The Hebrew word translated “buy” at Proverbs 23:23 can also mean “acquire.” Both words imply making an effort or exchanging something for an item of value. We might illustrate the idea of buying truth this way. Let us say that a market advertises “Free Bananas.” Will those bananas miraculously appear on our table? No. We have to make the effort to go to the market to pick them up. Are the bananas free? Yes, but we must expend the effort and take the time to go to the market. Similarly, we do not need money to buy truth. However, we must make an effort to obtain it. w18.11 1:4-5