This sermon outlines the believer's responsibility to share the gospel, drawing primarily from 2 Corinthians 5:14-20. The preacher identifies three key aspects of this duty: motivation through Christ's love, transformation into a new creation, and the role as an ambassador representing Jesus to the world. Emphasizing that salvation brings a radical change in perspective, the message urges Christians to live distinctively and actively witness to lost sinners. The central appeal is for believers to fulfill their obligation by presenting God's offer of reconciliation to others with urgency and integrity.