The doctrine of God's covenant as the foundational framework for understanding Scripture, emphasizing that salvation is entirely the result of God's sovereign, voluntary condescension—initiated not by human effort but by divine grace. It distinguishes between the covenant of works, implied but not named in the confession, and the covenant of grace, which is the sole means of salvation for fallen humanity, revealed progressively from Eden through the Old Testament covenants and fully realized in Christ. The covenant of grace is grounded in the eternal covenant of redemption between the Father, Son, and Holy Spirit, and its substance lies in God's free offer of life through faith in Christ, secured by the Holy Spirit's work in the elect. The sermon underscores the exclusivity and certainty of this covenant, affirming that no other covenant or human effort can bring salvation, and concludes with a call to trust in God's unbreakable promise, finding assurance and comfort in His everlasting, ordered, and secure covenant of grace.