v1-2: Paul's greeting follows that of the first letter (1 Thess 1.1).
v3: Paul commends them for real spiritual growth. Love was abounding, and faith was growing; Col 1.4; 1 Thess 1.3; 3.12; 4.10. Paul feels compelled to give God thinks for this growth.
v4: Following Paul's teaching about afflictions, he notes that their patience and faith were being maintained through persecutions and tribulations.
v5: Persecutions are a manifest evidence of the righteous judgment of God; not necessarily something to be avoided. In Phil 1.28, persecutions are clearly set forth as a proof of salvation, and that from God. It is through such experiences that our faith is strengthened, and we are counted worthy of the kingdom of God.
v6: "Those who trouble you"; in Gal 1.7, this refers to those who bring in false doctrine. This is described in the same way as the bringing in of persecution.
Suffering tribulation is a symptom of on going spiritual conflict; we need to look behind the symptoms and circumstances.
v7: We experience trouble today; but our hope is in Christ's revelation. Our relief may not be in this life.
v8: The revelation of Christ, to bring judgment upon unbelievers; they do not know God, and they do not obey the gospel of Christ.
v9: There is everlasting destruction, that is, on-going suffering. Such people are put away from the presence of the Lord, and the glory of His power, away from all that is good.
v10: 1 Thess 4.16-17 refers to the in-gathering of believers; at this time, unbelievers are separated for the judgment due to them. At the centre of all things is Jesus Christ; He is admired by all who are gathered to Him.
v11-12: In the delay before Christ's return, God is at work in His people, Phil 1.6; 2.13. The aim is that Christ is glorified in and through us.