1 Timothy 2:7
Whereunto I am ordained a preacher, and an apostle, (I speak the truth in Christ, [and] lie not;) a teacher of the Gentiles in faith and verity.
Note 15 at 1Ti 2:7: Paul was ordained a preacher and an apostle. The word "ordained" is the Greek word "TITHEMI," and this Greek word means "to place" (Strong's Concordance). "Preacher" (Greek - "KERUX"), in its common use in the first century, was "a herald, a messenger vested with public authority who conveyed the official messages of kings, magistrates, princes, military commanders, or who gave a public summons or demand" (Wuest Word Studies from the Greek New Testament, Volume 2, p. 43). This describes those who delivered public notices on the behalf of a sovereign, adding nothing more than what was told to them.
Paul explained to the people that as heralds are sent by the king or magistrate to deliver a message, he was sent by the Lord to share the Gospel.
Note 16 at 1Ti 2:7: Paul said in this parenthetical phrase that he was telling the truth and speaking no lie. That he inserted this suggests that his apostolic authority had been under question in Ephesus as it was in so many other places.
Note 17 at 1Ti 2:7: The Lord specifically commissioned Paul to preach the Gospel to the Gentiles. He certainly did that; however, he constantly sought to minister to the Jews and often expressed his longing to see his fellow Jews receive salvation (see note 3 at Ro 9:3). Much of his persecution came from the Jews. Therefore, it is possible that much of the persecution Paul endured could have been avoided if he had just done what the Lord had commissioned him to do.