In this sermon, the preacher focuses on John chapter 13, where Jesus teaches his disciples about the true source of power. He emphasizes that power is not found in worldly wealth, status, or power, but in a different way of thinking that is foolishness to those who do not have a spiritual understanding. The preacher also references the story of King Saul facing the giant Goliath in 1 Samuel 17, drawing parallels to the challenges faced by believers today. The sermon concludes with an invitation for the congregation to respond by humbling themselves and asking Jesus to wash their feet, symbolizing a willingness to serve others and die to self.

Horatius Bonar emphasizes the futility of human remedies in addressing spiritual afflictions, using Saul's disobedience and subsequent torment as a cautionary tale. He illustrates how Saul's reliance on external comforts, like David's harp, provided only temporary relief without addressing the root cause of his spiritual turmoil. Bonar warns against the modern tendency to seek solace in worldly distractions and religious rituals that fail to bring true healing and reconciliation with God. He contrasts this with David's reliance on divine strength, highlighting that true victory comes from faith in God rather than human contrivances. The sermon calls believers to abandon self-reliance and trust solely in God's power for true transformation.