The central message of this sermon is that being a Christian is not just about having a certain identity or position in Christ, but also about living out that identity and defending it against the forces of evil. The three verbs "sit," "walk," and "stand" represent different aspects of the Christian life: resting in the finished work of Christ (sit), living out one's faith and conducting their life in accordance with their new identity (walk), and standing firm against temptation, sin, and spiritual attacks from the devil (stand). The sermon emphasizes that understanding and resting in one's identity in Christ is not enough; it must be lived out and defended daily through putting on the full armor of God. Ultimately, the takeaway is that being a Christian requires a deep commitment to living out one's faith, standing firm against evil forces, and trusting in the power of God, rather than relying solely on personal strength or morality. This sermon advances the idea that Christianity is not just about individual salvation, but also about communal struggle and spiritual warfare, and encourages listeners to live out their faith with courage, resilience, and trust in God's provision.