Romans 15:20

Then when he says, and I have so preached, he shows how difficult it is to produce this fruit, for it is difficult to convert those entirely ignorant to the faith. First, therefore, he mentions the difficulty, saying: and I have so preached this Gospel, …

I not only preached the gospel to these and so many peoples and converted them, but I also did not go to those people to whom the name of Christ had already been proclaimed. So far am I from subjecting other people's disciples to myself …

Not where Christ had been named - These places he generally declined, though not altogether, having an holy ambition (so the Greek word means) to make the first proclamation of the gospel in places where it was quite unheard of, in spite of all the difficulty and dangers that attended it.

And commonly the greatest success of the gospel is at its first coming to a place; afterwards people become sermon-proof. The great and wonderful success that he had in his work: It was effectual to make the Gentiles obedient. The design of the gospel is to bring people to be obedient; it is not only a truth to be belie

Yea, so have I strived to preach the Gospel,....

For I will not dare to speak of any--"to speak aught" of those things which Christ hath not wrought by me--a modest, though somewhat obscure form of expression, meaning, "I will not dare to go beyond what Christ hath wrought by me"--in which form accordingly the rest of the passage is expressed.

Yea, so have I strived - The word used here φιλοτιμούμενον philotimoumenon means properly “to be ambitious, to be studious of honor;” and then to “desire” earnestly. In that sense it is used here. He earnestly desired; he made it a point for which he struggled, to penetrate into regions which had not heard the gospel. Not where Christ was named - Where the gospel had not been before preached. Lest I should build ... - That is, he desired to found churches himself; he regarded himself as particularly called to this. Others might be called to edify the church, but he regarded it as his function to make known the name of the Saviour where it was not before known. This work was particularly adapted to the ardor, zeal, energy, and bravery of such a man as Paul. Every man has his proper gift; and there are some particularly suited to “found” and establish churches; others to edify and comfort them; compare 2Co 10:13-16. The apostle chose the higher honor, involving most danger and responsibility; but still any office in building up the church is honorable.