William MacDonald emphasizes that human judgment is often flawed and can lead to disastrous outcomes, as illustrated by the example of a pilot who, deprived of oxygen, misjudged his ability to solve problems. He draws parallels to spiritual matters, where individuals mistakenly believe that good works can earn them salvation, despite the truth that only faith in Jesus Christ can lead to eternal life. MacDonald urges listeners to trust in God's Word rather than their own understanding, as true safety and salvation come from recognizing one's sinfulness and accepting Christ as Savior.

"There is a may which seemeth right unto a man; but the end thereof are the ways of death. " Proverb 14:12 Twice in the book of Proverbs (14:12 and 16:25) we learn that man's judgment as to the right way is not reliable. What seems right to him ends in disaster and death. During World War II the Navy gave a vivid illustration of this to its flight personnel. It was tying to impress on them that when they were flying at high altitudes and did not use their oxygen, they could not trust their senses. A pilot was instructed to enter a decompression chamber and sit down at a table on which was a sheet of mathematical problems. Oxygen was withdrawn from the chamber to simulate high altitudes. When the air became less dense, the pilot was told to solve the problems. He was also told that no one had done so correctly so far. The pilot would breeze through the problems with utmost confidence that he had beaten the system. The problems seemed easy, and he had every assurance that he would receive a perfect score. There was no doubt in his mind about it. But when oxygen was fed back into the chamber, and he emerged to have his paper corrected, he learned that his ability to solve problems had been seriously impaired by the lack of oxygen getting to his brain. The lesson was, of course, that if he flew at high altitudes without using his oxygen, he wouldn't be able to trust his own judgment, and he would be inviting a crash. Man's judgment has been seriously impaired by sin. He feels absolutely sure that the way to heaven is by doing the best he can. If you tell him that no one has ever been saved by good works, he still has every confidence that he will be the first to beat the system. He is certain that God would never turn him away from the gates of heaven. But he is wrong, and if he persists in his lack of "spiritual oxygen", he will perish. His safety lies in trusting the Word of God rather than his own judgment. If he does so, he will repent of his sins and receive the Lord Jesus Christ as his Lord and Savior. Because God's Word is truth, those who believe it can be confident that they are following the right route.