Pastor Van's sermon "Sinking Battleships" in "The Way of Wisdom" series stresses the importance of not relying on our own wisdom but trusting in God's guidance. He discusses the folly of being wise in our own eyes, using personal anecdotes and biblical references to illustrate the contrast between following God's ways and our own desires. Emphasizing the benefits of seeking God's wisdom through prayer, Pastor Van urges the congregation to surrender to God, listen to His guidance, and avoid the pitfalls of being wise in our own eyes. The sermon ends with a call to obedience and trust in God's ways for health and vitality.