1 Thessalonians 3:2
And sent Timotheus, our brother, and minister of God, and our fellowlabourer in the gospel of Christ, to establish you, and to comfort you concerning your faith:
Note 3 at 1Th 3:2: While Paul continued to work in Athens, he sent Timothy to minister to the Thessalonians. Paul intended for Timothy to accomplish two main things: to establish and to comfort.
The English word "establish" was translated from the Greek verb "STERIZO," which was used thirteen times in the New Testament. STERIZO means "to make stable, place firmly...to strengthen" (Thayer's Greek-English Lexicon). The word was used of stabilizing an existing structure. It came to be used figuratively of strengthening and stabilizing the believers.
The word "comfort" came from the Greek verb "PARAKALEO," and it was used 109 times in the N.T. This word carries the idea of encouraging and strengthening by consolation. A variation of this Greek word was translated "Holy Spirit," because "to comfort" is descriptive of the ministry of the Holy Spirit. The same word is used of Christ in 1Jo 2:1, where it means a legal advocate.
The Phillips New Testament Bible translates 1Th 3:1-2 as "And so at length, when the separation became intolerable, we thought the best plan was for me to stay in Athens alone, while Timothy, our brother and fellow-worker in the Gospel of Christ, was sent to strengthen and encourage you in your faith."