To which I have been appointed Not without good reason does he so highly commend the gospel along with his apostleship. Satan labors, beyond all things else, to banish from our hearts, by every possible method, the faith of sound doctrine; and as it is not always easy for him to do this if he attack us in open war, he steals upon us by secret and indirect methods; for, in order to destroy the credibility of doctrine, he holds up to suspicion the calling of godly teachers. [1] Paul, therefore, having death before his eyes, and knowing well the ancient and ordinary snares of Satan, determined to assert not only the doctrine of the gospel in general, but his own calling. Both were necessary; for, although there be uttered long discourses concerning the dignity of the gospel, they will not be of much avail to us, unless we understand what is the gospel. Many will agree as to the general principle of the undoubted authority of the gospel, who afterwards will have nothing certain that they can follow. This is the reason why Paul expressly wishes to be acknowledged to be a faithful and lawful minister of that life-giving doctrine which he had mentioned. A herald, and an apostle, and a teacher of the Gentiles For the reasons now stated, he adorns himself with various titles for expressing one and the same thing. He calls himself a herald, whose duty it is, to publish the commands of princes and magistrates. The word apostle is here used in its ordinary and restricted meaning. Moreover, because there is a natural relation between a teacher and his disciples, he takes to himself also this third name, that they who learn from him may know that they have a master who has been appointed to them by God. And to whom does he declare that he was appointed? To the Gentiles; for the main hinge of the controversy was about them, because the Jews denied that the promises of life belonged to any others than to the fleshly children of Abraham. In order, therefore, that the salvation of the Gentiles may not be called in question, he affirms that to them he has been especially sent by God.

Footnotes

1 - "Des Docteurs ou Pasteurs fideles." -- "Of faithful Teachers or Pastors."

Whereunto I am appointed a preacher - That is, I am appointed to make these truths known; see the notes at Ephesians 3:7-8.

Whereunto I am appointed a preacher - Κηρυξ, a herald. See the notes at Matthew 3:17.
And an apostle - Sent immediately from God to man.
A teacher - One whose business it is to instruct men, and particularly the Gentiles, to whom he was especially sent; to proclaim the doctrines of eternal life, the resurrection and final incorruptibility of the human body; and, in a word, the salvation both of the body and soul of man by Christ Jesus.

(5) Whereunto I am appointed a preacher, and an apostle, and a teacher of the Gentiles.
(5) That is, the Gospel which the apostle preached.

Whereunto I am appointed a preacher,.... Both from eternity, in the counsel and purpose of God, Acts 9:15 and in time, by the church at Antioch, and the prophets in it, according to the express order of the Holy Ghost, Acts 13:2. And if ever there was a preacher of the Gospel, Paul was one; he preached purely, powerfully, publicly, constantly, boldly, and with all faithfulness and integrity:
and an apostle; that is, of the Gentiles, as follows, and as he elsewhere styles himself, Romans 11:13 for it does not run so smooth and easy to connect this with the word Gospel. In 2-Timothy 1:1, he is called the apostle of Jesus Christ, because he was sent by him; and here the apostle of the Gentiles, because, he was sent to them; and this by the same appointment, by which he became a preacher:
and a teacher of the Gentiles; though all the apostles, by their commission, were sent to teach all nations, or the Gentiles in the several parts of the world, as well as Jews; yet the apostle was eminently a teacher of them; his work chiefly lay among them; the Gospel of the uncircumcision, or the ministration of the Gospel to the uncircumcised Gentiles, was committed to him; and he was a teacher of them in faith and verity, as in 1-Timothy 2:7. The Alexandrian copy only reads, "and a teacher".

Whereunto--For the publication of which Gospel.
I am appointed--Greek, "I was appointed."
preacher--Greek, "herald."
teacher of the Gentiles-- (1-Timothy 2:7). He brings forward his own example in this verse and 2-Timothy 1:12, as a pattern for Timothy, as a public "preacher," an "apostle," or missionary from place to place, and a "teacher" in private instructing His flock with patient perseverance.