Thomas Brooks warns against the dangers of being earthly-minded, illustrating this through the parable of the rich man who focuses solely on his material wealth and comfort, neglecting thoughts of God and eternity. The rich man's preoccupation with his possessions leads to his downfall, as he fails to prepare for the afterlife. Brooks emphasizes that a life consumed by worldly concerns ultimately results in spiritual emptiness and divine judgment. He calls for believers to shift their focus from earthly treasures to heavenly pursuits, reminding them of the fleeting nature of life and the importance of eternal values.