John Nelson Darby expounds on Mark 10, emphasizing the corruption of God's creation due to sin and the importance of recognizing the true state of man before God. He illustrates how the law, while necessary, reveals humanity's inability to achieve righteousness on their own, as seen in the encounter with the rich young ruler who, despite his outward morality, is ultimately unable to follow Christ due to his attachment to wealth. Darby highlights that true goodness is found only in God, and that salvation is impossible for man without divine intervention. The sermon concludes with the reminder that while following Christ may involve suffering and sacrifice, it leads to eternal life and the fulfillment of God's promises.