I’ve included Father Callan’s summaries of Chapters 1:1-2:11 to help provide context. These summaries will be followed by his commentary on the Sunday Epistle reading. Text in red are my additions.
THE APOSTLE GREETS THE THESSALONIANS AND CONSOLES THEM
A Summary of 2 Thessalonians 1:1-12~After saluting the faithful at Thessalonica (ver. 1-2), the Apostle first thanks God for their faith, charity, and patient endurance of persecutions (ver. 3-4), and then describes the just judgment of God, which will reward them for their virtue and punish their oppressors (ver. 5-10). He concludes by assuring them that their Apostles are always praying for them, to the end that God may make them worthy of the call He has given them (ver. 11-12).
THE PAROUSIA IS NOT YET
A Summary of 2 Thessalonians 2:1-11~The faithful must not be disturbed about the Coming (Parousia) of the Lord, for certain signs, yet far off, must first precede that grand event. There must come first a great religious revolt, and then the man of sin. Antichrist, must appear, as was explained before in the Apostle’s preaching. This mystery of iniquity is already at work, but something holds back the full exercise of his power. He shall eventually be conquered by Christ coming in His glory, but
he will first show great signs and wonders and seduce many.
1:11. Wherefore also we pray always for you, that our God would make you worthy of his vocation, and fulfill with power all the good pleasure of his goodness and the work of faith;
In verses 11-12 St. Paul says that his continual prayer for his readers is that they may be made worthy of their lofty vocation, and that Jesus Christ may be glorified in them and they in Him.
Our God, i.e., the God of us all.
Of his vocation, i.e., of the call He has given you, so that one day you will be found worthy of the reward of glory to which you have been chosen.
And fulfill with power all the good pleasure, etc., i.e., powerfully fill you with a desire of every good that a righteous will could wish for (St. Thomas) and that faith can effect.
St Paul’s desire That our God would make you worthy of his vocation should be seen in opposition to the deleterious working and power of the Antichrist Whose coming is according to the working of Satan, in all power and signs and lying wonders: And in all seduction of iniquity to them that perish: because they receive not the love of the truth, that they might be saved (2:9-10). Likewise the words power, goodness, and work of faith should be seen in contrast to the power, evil and workings of Antichrist (2:9), and in contrast to those who follow him, upon whom God will send the “operation (i.e., working) of error, to believe lying: That all may be judged who have not believed the truth but have consented to iniquity.” (2:10-11).
Our God stands in marked opposition to Antichrist whom St Paul will describe as he Who opposeth and is lifted up above all that is called God or that is worshipped, so that he sitteth in the temple of God, shewing himself as if he were God (2:4).
1:12. That the name of our Lord Jesus may be glorified in you, and you in him, according to the grace of our God, and of the Lord Jesus Christ.
The final purpose of the Apostle’s prayer and of the sanctification of the faithful is that our Lord may be glorified in them, and that they in turn may be glorified in Him through the outpouring of His glory upon them in the beatific vision (cf. John 17).
The name stands for the person, according to Semitic usage.
According to the grace, etc. The grace of God, communicated through Jesus Christ, is the source of the sanctification of the faithful.
2:1. And we beseech you, brethren, touching the coming of our Lord Jesus Christ, and of our gathering together unto him:
Touching the coming of our Lord, etc., i.e., on behalf of the Parousia, or Second Coming of Christ to judge the world.
And of our gathering together, etc. Better, “and of our being gathered together, etc.,” referring to the reunion of the living and the dead at the coming of our Lord at the end of the world (1 Thess. 4:17, 5:10).
2:2. That you be not easily moved from your sense, nor be terrified, neither by spirit, nor by word, nor by epistle, as by us, as if the day of the Lord were at hand.
The Apostle asks the Thessalonians that they be calm and peaceful, that they do not lose their “sense” (i.e., their prudent and sober judgment), nor be greatly disturbed, as if the Parousia were at hand.
By spirit, i.e., by any pretended revelation or prophesy attributed to the Holy Ghost.
Nor by word, i.e., any utterance or teaching based on a pretended revelation or prophesy, or on some utterance of the Apostle, misinterpreted or falsely attributed to him.
Nor by epistle, as by us, etc., i.e., any spurious letter circulated in the name of Paul, or false explanation of his first Epistle to the Thessalonians. Let none of these sources of error lead them to think the Second Advent is upon us.
Easily moved would be better translated as suddenly shaken. The Greek for shaken can also have the meaning seized. The warning stands related to 2:15. An interpretive translation of that verse which might help bring out the connections is as follows: “Therefore, brothers, stand firm (don’t be shaken), and hold fast (don’t be seized) to the traditions you have received.”