J.C. Ryle emphasizes the significance of belonging to the true Church built upon Christ, which is not a physical structure but a spiritual body of true believers. He explains that this Church is founded on the revelation of Christ as the Savior and is sustained by the work of the Holy Spirit. Ryle warns against the dangers of false churches and encourages individuals to ensure their personal connection to Christ, as only those truly joined to Him will find salvation. He reassures that despite the trials and opposition faced by the Church, the gates of hell will not prevail against it, affirming the eternal security of believers. Ryle concludes with a call to live holy, courageous, and joyful lives as members of this Church on the rock.