C.H. Spurgeon emphasizes the privilege and joy of preaching the gospel, as exemplified by the apostle Paul, who found humility in his calling despite his success. He illustrates that true humility comes from hard work and the recognition of one's own weaknesses, especially when proclaiming the unsearchable riches of Christ. Spurgeon encourages believers to follow Paul's example by focusing solely on Christ and His crucifixion in their ministry. He likens Christians to flowers that open to the sun, suggesting that Jesus should be the source of their strength and inspiration. Ultimately, the message of Christ is both nourishing and transformative for both the speaker and the listener.

The apostle Paul felt it a great privilege to be allowed to preach the gospel. He did not look upon his calling as a drudgery, but he entered upon it with intense delight. Yet while Paul was thus thankful for his office, his success in it greatly humbled him. The fuller a vessel becomes, the deeper it sinks in the water. Idlers may indulge a fond conceit of their abilities, because they are untried; but the earnest worker soon learns his own weakness. If you seek humility, try hard work; if you would know your nothingness, attempt some great thing for Jesus. If you would feel how utterly powerless you are apart from the living God, attempt especially the great work of proclaiming the unsearchable riches of Christ, and you will know, as you never knew before, what a weak unworthy thing you are. Although the apostle thus knew and confessed his weakness, he was never perplexed as to the subject of his ministry. From his first sermon to his last, Paul preached Christ, and nothing but Christ. He lifted up the cross, and extolled the Son of God who bled thereon. Follow his example in all your personal efforts to spread the glad tidings of salvation, and let "Christ and Him crucified" be your ever recurring theme. The Christian should be like those lovely spring flowers which, when the sun is shining, open their golden cups, as if saying, "Fill us with thy beams!" but when the sun is hidden behind a cloud, they close their cups and droop their heads. So should the Christian feel the sweet influence of Jesus; Jesus must be his sun, and he must be the flower which yields itself to the Sun of Righteousness. Oh! to speak of Christ alone, this is the subject which is both "seed for the sower, and bread for the eater." This is the live coal for the lip of the speaker, and the master-key to the heart of the hearer.