The sermon recounts the story of a missionary's work in Mexico, highlighting the importance of faithfulness and engagement in God's harvest. Drawing from the example of Ruth, the message emphasizes the need to keep one's eyes on the field, remain steadfast until the end, and avoid going home empty-handed when the Lord returns. The speaker underscores the significance of active participation in ministry, supporting missionaries, and embracing the opportunities to serve, ultimately aiming for a life of purpose, peace, and joy in alignment with God's will.