In the Epistle of Jude

Jude writes that he was very eager to write to you about the salvation we share. Jude 1:3

Eternal Life, or the afterlife, is interpreted differently by different religions. There is a vast difference between the world's religions and Christian denominations. World religions do not include salvation; saved by faith through grace.

Whereas in Christianity, we are saved by our faith in The Lord Jesus Christ through the grace he extends to those who believe. The Bible has much to say about this: when to get saved, today, where, anywhere, how—call on the name of the Lord for forgiveness.

Eternal life is, indeed, eternal, not temporary. We have been chosen, called, drawn, enabled, qualified, and sealed by God to God through our Lord Jesus Christ into an eternal kingdom.