The Bible tells us that everyone will exist forever, either in heaven or in hell; These will go away into eternal punishment, but the righteous into eternal life. (Matthew 25:46)
Eternal life is, however, more than just an eternal existence in heaven. Eternal life is the glorious gift of personally knowing and being with God forever; This is eternal life, that they may know you, the only true God, and Jesus Christ whom You have sent. (John 17:3) Believers have this eternal life now, as well as, forever; ...I came that they might have life and have it abundantly. (John 10:10)
Those who do not know Jesus Christ as their Lord and Savoir will suffer eternal death, separated from God forever in hell. And even when an unbeliever is physically alive, they are spiritually dead, separated from the living God; And you were dead in your trespasses and sins. (Ephesians 2:1)
Jesus Christ alone provides and offers the free gift of eternal life with God now and forever; Jesus said to him, "I am the way, and the truth, and the life; no one comes to the Father but through Me." (John 14:6) Maranatha!