After he told the brethren to “stand fast and hold the traditions which you were taught, whether by word or our epistle” the apostle Paul offered a prayer on their behalf.
The prayer was for “our Lord Jesus Christ Himself, and our God and Father” to comfort the Thessalonians and establish them in their good words and works. To stand fast in the inspired traditions of the apostles the Thessalonians had to do, and say good things. Christians are expected to be involved in good works (cf. Ephesians 2:10). They are also expected to speak the oracles of God, and things that might impart grace to the hearers (cf. 1 Peter 4:11; Ephesians 4:29). This was possible only through the strength given by Christ, and God (cf. Philippians 4:13).
The petition raised by Paul for the Thessalonians was for the help of Jesus, and God. God and Christ had already expressed their love to the Thessalonians by the revealing of the truth, and the sanctification they received by their obedience (v. 13). They had received encouragement by the “good hope” they had been given by via grace of God. The hope of heaven allows for Christians to persevere, and remain comforted in difficult times of suffering, and trials (cf. Romans 8:18, 25). Thank God for His comfort with which we can comfort others (cf. 2 Corinthians 1:3-7), and the hope we have that sustains us until that great day!