John thought a lot about innovative ways to convey Bible truths. One day, to teach the Second Coming of Christ, he cut the heads off half a dozen nails. Next he shaped scrap aluminum to look like nails. A magnet picked up the steel nails but left the aluminum counterfeits. “When Jesus comes, He will take only those who are truly His. Some of you have been listening to God’s Word, you’ve been teaching God’s Word, but you have not really become Christians. God knows your hearts.”
John cut out little tin and aluminum men. At the next lesson he showed the class how only the tin men were attracted by the magnet.
Again he taught, “When Jesus Christ comes again, only true believers (tin men) will go with Him. The others (aluminum men) will be left because even though they look the same as the true believers, they have not been changed in their hearts. When Jesus comes, some of you will be caught up, some will be left behind. Jesus is coming soon. It may be today. We must get ready!”
A young man, Wabinan, was one who listened. Afterward he told John, “I am not ready. I want to follow Jesus here and go with Him when He comes:” From then on, he sought God with his whole heart.
Dekker, John (with Lois Neely). Torches of Joy. Seattle: YWAM Publishing, 1985, 1999 p. 90-91