We give thanks to God always for you all, making mention of you in our prayers; remembering without ceasing your work of faith and labor of love and patience of hope in our Lord Jesus Christ, before our God and Father; knowing, brethren beloved by God, His choice of you; for our gospel did not come to you in word only, but also in power and in the Holy Spirit and with full conviction; just as you know what kind of men we proved to be among you for your sake. You also became imitators of us and of the Lord, having received the word in much tribulation with the joy of the Holy Spirit, so that you became an example to all the believers in Macedonia and in Achaia.
David Guzik comments: “Paul himself founded the church in Thessalonica on his second missionary journey (Acts 17:1-9). He was only in the city a short time because he was forced out by enemies of the gospel. But the church of the Thessalonians left behind was alive and active. Paul’s deep concern for this young church he had to suddenly leave prompted this letter.” (David Guzik’s Commentaries on the Bible)
Guzik also adds: “No doubt he was greatly concerned about the churches he had just founded - how were they doing? While at Corinth, Silas and Timothy came to him from Thessalonica with great news: the church there was going strong, and Paul got so excited that he dashed off this letter to the Thessalonians, probably his first letter to any church. He wrote it just a few months after he had first established the church in Thessalonica. After writing and sending this letter, Paul enjoyed a sustained and fruitful ministry in Corinth - and eventually returned to the Thessalonians.” (David Guzik’s Commentaries on the Bible)
However, from the Calvinist perspective, this would mean that God’s “choice” of them, was to bring them the Gospel in such a way, that it wasn’t in “word only,” but with “power,” that is, with “the Holy Spirit,” accompanying “full conviction,” viz. Irresistible Grace:
Calvinist, William MacDonald, comments: “The apostle was assured that these saints had been chosen by God before the foundation of the world. But how did he know? Did he have some supernatural insight? No, he knew they were among the elect by the way they had received the gospel.” (Believer’s Bible Commentary, p.2024, emphasis mine)
John Calvin writes: “He mentions their calling, and since it had displayed exceptional marks of God’s power, he infers from it that they had been particularly called with evidence of certain election.” (Calvin’s New Testament Commentaries: Romans and Thessalonians, p.335, emphasis mine, emphasis mine)
Calvin adds: “It is to be noted, however, that the election of God, which by itself is hidden, is made known by its marks, when God gathers to Himself the lost sheep, and joins them to His flock, and stretches out His hand to those who are wandering and estranged from Him. The knowledge of our election, therefore, must be sought from this source. But just as the secret counsel of God is a labyrinth to those who disregard His calling, those who under the pretext of faith and calling obscure this first grace, from which faith itself flows, are obstinate in their error. ‘By faith,’ they say, ‘we obtain salvation. There is, therefore, no grace of God which lightens us to faith.’ It is not so, but as free elections must be connected with calling, as though with its effect, so in the meantime it must retain its primacy.” (Calvin’s New Testament Commentaries: Romans and Thessalonians, p.336, emphasis mine, emphasis mine)
Actually, Arminians absolutely do insist that there is a “grace which lightens us to faith” (i.e. Prevenient Grace), but that it is resistible, rather than being irresistible as Calvinism teaches. Giving John Calvin the benefit of the doubt, perhaps he had the Pelagians in mind, although some Calvinists such as R.C. Sproul feel that the difference between Arminianism and Pelagianism is a “distinction without a difference” since in both systems, the final choice to accept or reject God’s grace is still left up to the individual, and Sproul is certainly welcome to his perspective, but nonetheless, here you can see in Calvin’s quote, that there is a very real distinction between Arminianism and Pelagianism, as Arminians insist that God’s enabling grace is absolutely essential, rather than being altogether absent.
In terms of MacDonald’s comment, Calvinists suppose that there is such a thing as an elect unbeliever, which is absolutely absurd because according to Romans 9:33, the elect are free from condemnation, while according to John 3:18, unbelievers are enslaved to condemnation. Therefore, you cannot have an elect [redeemed] unbeliever [condemned]. Calvinists have set up an impossible situation, and yet they insist upon it anyway, as MacDonald further points out: “We do not know who the elect are, and so we should carry the gospel to all the world.” (Believer’s Bible Commentary, p.2024, emphasis mine) However, I can tell you who the elect are. They are Christians, that is, the redeemed in Christ. (Romans 8:1, 33) Colossians 3:12-13 states: “So, as those who have been chosen of God, holy and beloved, put on a heart of compassion, kindness, humility, gentleness and patience; bearing with one another, and forgiving each other, whoever has a complaint against anyone; just as the Lord forgave you, so also should you.” Now, seriously, how could that, in any way, apply to an unbeliever? That’s why I believe that it is evident that the elect, in New Testament terms (in contrast to the elect Jews of the Old Testament), are Christians...not unbelievers predestined to salvation, but Christians.