G. Campbell Morgan emphasizes the profound message of Isaiah, focusing on the dual themes of God's government and grace. He explains that God's government is characterized by holiness, righteousness, and justice, while His grace is the underlying principle that informs these characteristics. Morgan highlights the necessity of submission to God's government as essential for human fulfillment and the restoration of those broken by sin. The sermon illustrates that the relationship between government and grace is interdependent, with grace not vacating God's authority but enhancing it. Ultimately, the message of Isaiah reveals the unwavering Throne of God, where justice and love coexist, culminating in the sacrificial Lamb.