1 Paul, Silvanus, and Timothy, to the church of the Thessalonians in God our Father and the Lord Jesus Christ: 2 Grace to you and peace from God our Father and the Lord Jesus Christ.
3 We are bound to thank God always for you, brothers, as it is proper, because your faith grows exceedingly and the charity of each one of you all toward one another abounds, 4 So that we ourselves glory in you in the churches of God for your patience and faith in all your persecutions and tribulations that you endure. 5 This is a manifest token of the righteous judgment of God, that you may be counted worthy of the kingdom of God, for which you also suffer, 6 Seeing it is a righteous thing with God to recompense tribulation to those who trouble you, 7 And rest to you who are troubled, and also to us, when the Lord Jesus is revealed from heaven with his mighty angels, 8 In flaming fire, taking vengeance on those who do not know God and who do not obey the gospel of our Lord Jesus Christ. 9 They shall be punished with everlasting destruction from the presence of the Lord and from the glory of his power, 10 When he comes to be glorified in his saints and to be admired by all those who believe (because our testimony among you was believed) in that day. 11 Therefore, we also pray always for you, that our God would count you worthy of this calling and fulfill all the good pleasure of his goodness and the work of faith with power, 12 So that the name of our Lord Jesus Christ may be glorified in you and you in him, according to the grace of our God and of the Lord Jesus Christ.
[v.8] - "taking vengeance" - Reference, Deuteronomy 32:35; Romans 12:19.