'Eternal' in the Bible

And [the] angels who did not keep to their own domain but deserted their proper dwelling place, he has kept in eternal bonds under deep gloom for the judgment of the great day,

as Sodom and Gomorrah and the towns around them indulged in sexual immorality and {pursued unnatural desire} [in] the same way as these, are exhibited as an example [by] undergoing the punishment of eternal fire.

keep yourselves in the love of God, looking forward to the mercy of our Lord Jesus Christ to eternal life.