'Eternal' in the Bible

and He has kept, with eternal chains in darkness for the judgment of the great day, the angels who did not keep their own position but deserted their proper dwelling.

In the same way, Sodom and Gomorrah and the cities around them committed sexual immorality and practiced perversions, just as angels did, and serve as an example by undergoing the punishment of eternal fire.

keep yourselves in the love of God, expecting the mercy of our Lord Jesus Christ for eternal life.