John Vissers concludes the series on Jonah by exploring the profound compassion of God as illustrated in Jonah chapter 4. He highlights Jonah's anger at God's mercy towards Nineveh, contrasting it with God's sovereign grace and concern for the lost. Vissers emphasizes that God's compassion is limitless and challenges believers to expand their hearts to reflect God's love for all people. The sermon culminates in the reminder that the ultimate expression of God's mercy is found in the sacrifice of Jesus Christ, inviting the congregation to approach the Lord's Supper with faith and repentance.