To me, though I am the very least of all the saints, this grace was given, to preach to the Gentiles the unsearchable riches of Christ.Ephesians 3:8
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. Although Paul was thankful for his calling, his success in it greatly humbled him.
The fuller a ship 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 want to 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 on it. 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 that, when the sun is shining, open their golden cups, as if saying, "Fill us with your 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 that yields itself to the Sun of Righteousness.
Oh, to speak of Christ alone--this is the subject that is both "seed to the sower and bread to the eater."1 This is the live coal for the lip of the speaker, and the master-key to the heart of the hearer.
1) Isaiah 55:10