2-timothy 1:1

Apostle - Messenger; one who has been sent.

Paul an apostle - St. Paul at once shows his office, the authority on which he held it, and the end for which it was given him. He was an apostle - an extraordinary ambassador from heaven. He had his apostleship by the will of God - according to the counsel and design of God's infinite wisdom and goodness. And he was appointed that he might proclaim that eternal life which God had in view for mankind by the incarnation of his Son Jesus Christ, and which was the end of all the promises he had made to men, and the commandments he had delivered to all his prophets since the world began. The mention of this life was peculiarly proper in the apostle, who had now the sentence of death in himself, and who knew that he must shortly seal the truth with his blood. His life was hidden with Christ in God; and he knew that, as soon as he should be absent from the body, he should be present with the Lord. With these words he both comforted himself and his son Timothy.

Paul, an apostle of Jesus Christ, - See the notes at Romans 1:1.

By the will of God - Called to be an apostle in accordance with the divine will and purpose; see the notes at Galatians 1:1.

According to the promise of life which is in Christ Jesus - In accordance with the great promise of eternal life through the Saviour; that is, he was called to be an apostle to carry out the great purpose of human salvation; compare Ephesians 3:6. God has made a promise of life to mankind through faith in the Lord Jesus, and it was with reference to this that he was called to the apostleship.