John Nelson Darby explores the depth of the apostle Paul's heart in 1 Corinthians 4, emphasizing the irony in the Corinthians' self-perception of being rich and reigning as kings. He highlights that true judgment comes from God, not from self-assessment, and that all gifts and differences among believers are given by God. Darby also notes Paul's gentle assertion of authority and his commitment to teaching the ways of Christ and the kingdom of God, reminding the Corinthians of their unity in Christ and the source of their gifts.