A.B. Simpson expounds on Isaiah's vision of the future glory of Israel and Jerusalem, contrasting it with the current state of corruption and sin. He emphasizes the centrality of the Lord's house, which will be exalted above all nations, drawing people to God and establishing peace on earth. Simpson highlights the need for repentance and the transformative power of the Holy Spirit, reminding believers that a remnant will be saved and prepared for the coming glory. He encourages the congregation to hold onto the vision of hope amidst present darkness, assuring them that God's promises will be fulfilled.