Such is the law governing the appearance on earth of the truth about Christ Jesus: the division of men and the rising of some against others (Mt 10:35-37). Those who do not receive the word of God arm themselves against those who receive and bear it, and persecute them. So it was in Judea, so it is everywhere, and so it is among you.
The fact that men rose against you is no reproach to the word and no undermining of its truth. On the contrary, it proves that the word is extraordinary, not earthly, but divine.
For shows that the Apostle is giving a reason here. For what? For what he had just said, that the word preached by them and received by the Thessalonians is divine and produces divine power and action in them.
How do hostility and persecution from one's own people serve as proof of this? In this way: the received word, by the action of grace, changed the thoughts, morals, and conduct of those who believed. This separated them from their own people and armed the latter against them.
Persecutions prove the divine character of the word because they point to an essential change in the minds and hearts of believers. Such a change could not have occurred if the word were not divine. On the other hand, the persecuted endure and stand firm in what is theirs. Whence comes this? From the same power of the word received with faith.
Thus the divine character of the word is proved both by the existence of persecution and by the fact that those who received the word remain faithful to it despite this persecution. Saint Chrysostom says: "He proves that they received the word properly by the trials to which they were subjected. How, he says, would you have endured such dangers if you had not attended to our words as to the words of God Himself?"
Oecumenius adds: "That you received our word as the word of God is evident from the fact that you were able to endure such afflictions. As above the Apostle proved from what he himself suffered that he preaches what is divine, so now from what they suffered he proves that they received his preaching as the word of God." The same is found in Theophylact.
By comparing the Church of Thessalonica with the Churches of Judea, he grants it great honor and inspires it to patience. Even proselytes from the Gentiles were accustomed to look upon Jerusalem and Judea as the sanctuary of God's truth. All the more reverently, then, should Christians from the Gentiles have regarded those who were there.
There the Lord acted, there the Holy Spirit descended, there the first Churches were founded, and from there the Apostles went forth into the whole world. The Churches there were exemplary, and to become like them was glory for Christians living far away. Here the prophecy of Saint Isaiah was fulfilled, concerning the glory of Zion and the desirable movement of the nations toward it for enlightenment and truth (Isa 2:2-3).
Having pointed to the Churches in Judea, the Apostle characterizes them thus: the churches of God in Christ Jesus, in order to show that not all communities there are true Churches. "Since the Jewish synagogues also appeared to be in God, the Apostle says of the Churches of believers that they are not only in God, but also in Christ Jesus. For he who rejects the Son has also rejected the Father" (Oecumenius, and similarly Theophylact).
Here too the Apostle has the same aim: to hold the Thessalonians' attention on the thought of the division everywhere produced by the word of truth that they preach. This was necessary for him in order to remove the perplexity prompted by the unbelief of the Jews.
How is it, they might say, that the Jews, worshippers of the true God and guardians of His revelations, do not believe you? Surely your words are not from God? The Apostle breaks this perplexity by saying that not all disbelieve. Then, in verses 15 and 16, he portrays the unbelieving Jews in dark colors.
The better part of the Jews believed and formed glorious Churches in Christ Jesus. These very ones suffer from their own blood relatives, the Jews, as you suffer from your own countrymen. If all Jews failed to believe, the perplexity would be strong. But since whole Churches have been formed from them, this is a powerful proof of the truth of the word.
For those who believed suffer from their own people, and in such a case one must have stronger motives and grounds for faith than for unbelief. Unbelief would have left them in peace, amid the old order, which they themselves had formerly valued highly.
Saint Chrysostom says: "If the Jews too resolved to endure all things patiently for the faith, this serves as no small proof that the preaching is true." Theophylact continues the same thought: "It is no small proof of the truth of the Gospel that Jews willingly suffer for what they themselves formerly persecuted."
Having thus separated the believing Jews from the unbelieving, the holy Apostle lays the full weight of judgment strictly upon the latter.