F.B. Meyer emphasizes the importance of unity in the Church, drawing parallels from the unification of Israel under King David. He argues that true unity is achieved not through organizational efforts but by each individual heart enthroning Christ as King. Meyer warns against being double-minded, as true loyalty and service to God require a single-hearted devotion. He encourages believers to work together in harmony, as collective efforts yield greater results than individualistic pursuits. The sermon calls for Christians to maintain their ranks and support one another in the mission against the kingdom of Satan.