granting vindication, by a flame of fire, against those who do not know God and who are not obedient to the Gospel of our Lord Jesus Christ
Other versions
King James Version
In flaming fire taking vengeance on them that know not God, and that obey not the gospel of our Lord Jesus Christ: English Standard Version
in flaming fire, inflicting vengeance on those who do not know God and on those who do not obey the gospel of our Lord Jesus.New International Version
He will punish those who do not know God and do not obey the gospel of our Lord Jesus.