John Gill emphasizes the transient nature of the world and its desires, explaining that while the physical world and its pleasures are fleeting, those who do the will of God will endure forever. He highlights that worldly possessions and lusts are temporary and ultimately lead to sorrow, while true fulfillment comes from a relationship with Christ and obedience to God's will. Gill reassures believers that their eternal security is rooted not in their works, but in God's unchanging grace and the covenant established through Jesus.