D.L. Moody shares a poignant story of an elderly man who recalls a significant moment from his childhood when his father crafted a small cross, symbolizing God's love and the sacrifice of Jesus. This memory of the cross became a guiding truth in the man's life, illustrating the lasting impact of teaching children about the redemptive power of Christ's sacrifice. Moody emphasizes that instilling such truths in the hearts of children will accompany them throughout their lives, shaping their faith and understanding of God's love.