Andrew Bonar emphasizes the importance of seeking Christ's guidance in all actions, as demonstrated by the disciples who consulted Him before finding the upper room. He reflects on the honor of being able to serve Christ, comparing the man who lent the upper room to others who offered their possessions for His use. Bonar highlights the man's reverence for worship and love for Christ, noting that even a hint from the Master was enough for him to act. The sermon concludes with the idea that those who open their hearts to Christ will experience His presence and transformative power, making their lives memorable in His service.