In Pastor Ross's sermon on Matthew 6:19-34, the central message revolves around the significance of undivided allegiance to God's Kingdom. He emphasizes the need to prioritize seeking God's rule, living obediently, and demonstrating generosity in our lives, ultimately treasuring God above all else. The sermon highlights the contrast between healthy eyes, which represent a generous and God-centered approach to wealth, and unhealthy eyes, characterized by greed and materialism. It underscores that one cannot serve both God and money, calling for wholehearted devotion to God. Additionally, the sermon encourages trust in God's provision and emphasizes that worry and anxiety are unnecessary, as God will care for our needs just as He does for the birds and flowers.