Sent. — It may possibly mean that a message was despatched to him at Berœa, ordering him to go, but is far more naturally understood if Timothy were at Athens at the time.
And minister... — The text here, according to the judgment of most of the best editors (though Tischendorf in his last edition has modified his opinion), is interpolated, and the verse should run: “our brother, and God’s fellow-worker in the gospel of Christ.” Timothy being a person so well known at Thessalonica, it is difficult to see why he should be thus particularised, unless he was the bearer of the letter, and St. Paul wished to insist upon their paying him due deference in spite of his youth.
To establish, perhaps in the sense of perfecting their organisation.
To comfort is here equivalent to “to encourage.”