rendering vengeance to them that know not God, and to them that obey not the gospel of our Lord Jesus:

To give punishment to those who have no knowledge of God, and to those who do not give ear to the good news of our Lord Jesus:

εν πυρι φλογος, καμνων εκδικησιν εις τους μη γνωριζοντας Θεον και εις τους μη υπακουοντας εις το ευαγγελιον του Κυριου ημων Ιησου Χριστου,

In flaming fire taking vengeance on them that know not God, and that obey not the gospel of our Lord Jesus Christ:

punishing those who don’t know God, and to those who don’t obey the Good News of our Lord Jesus,