John Gill emphasizes the omnipotence of God, asserting that His power is inherent to His nature and essential for His divine attributes. He explains that God's omnipotence is evident in creation, providence, redemption, and the perseverance of believers, highlighting that nothing is impossible for God. Gill argues that God's power is absolute and unbounded, and that it is crucial for the fulfillment of His promises and the execution of His will. He also notes that while God cannot act contrary to His nature, this does not limit His omnipotence but rather affirms it. Ultimately, Gill's sermon serves to inspire awe and trust in God's limitless power.