Can we avoid all contact with the world’s thinking? No, we cannot literally get out of the world. Some exposure to its ideas is inescapable. (1 Cor. 5:9, 10) The preaching work itself will bring us in contact with erroneous beliefs. However, where contact with ungodly views is unavoidable, we certainly need not entertain them or accept them. Like Jesus, we should be quick to reject thoughts that serve Satan’s purpose. Furthermore, we can protect ourselves from unnecessary exposure to the world’s thinking. For example, we should exercise caution when choosing our close friends. The Bible warns that if we keep close company with people who do not worship Jehovah, their thinking will rub off on us. (Prov. 13:20; 1 Cor. 15:12, 32, 33) Also, by rejecting entertainment that promotes the theory of evolution, violence, or immorality, we avoid poisoning our thinking with ideas that are “against the knowledge of God.”​—2 Cor. 10:5. w18.11 21 ¶16-17

How can we strengthen our determination to go on walking in the truth? One way is to have as full a share as possible in teaching Bible truth to others. In this way you will keep a firm grip on our spiritual sword, which is “God’s word.” (Eph. 6:17) All of us can strive to improve our skills as teachers, “handling the word of the truth aright.” (2 Tim. 2:15) As we use the Bible to help others to buy truth and reject falsehoods, we embed God’s sayings in our own mind and heart. In this way, we strengthen our determination to go on walking in the truth. The truth is a precious gift from Jehovah. By means of this gift, we have our most prized possession, our intimate relationship with our heavenly Father. What he has taught us until now is only the beginning! God has promised us an eternity to add to the truth we have already bought. Therefore, cherish the truth like a fine pearl. Continue to “buy truth and never sell it.”​—Prov. 23:23. w18.11 8 ¶2; 12 ¶15-17

Noah’s preaching work prior to the Flood evidently included a warning of coming destruction. Note what Jesus stated: “For as they were in those days before the Flood, eating and drinking, men marrying and women being given in marriage, until the day that Noah entered into the ark, and they took no note until the Flood came and swept them all away, so the presence of the Son of man will be.” (Matt. 24:38, 39) Despite the people’s indifference, Noah faithfully proclaimed the warning message that he had been given. Today, we preach the Kingdom message to give people an opportunity to learn about God’s will for mankind. Like Jehovah, we dearly wish that people would respond to the message and “keep living.” (Ezek. 18:23) At the same time, when we preach from house to house and in public areas, we warn as many people as possible that God’s Kingdom will come and bring an end to this ungodly world.​—Ezek. 3:18, 19; Dan. 2:44; Rev. 14:6, 7. w18.05 19 ¶8-9