What happens to those that don’t know Jesus as their Savior (unbelievers)? When they die, they go to Hell. At the end of the Millennium, they will experience a second death at The Great White Throne of Judgment (Revelation 20:11-15), where they are cast into the Lake of Fire for eternity.
Everyone is supposed to die one time but, is only if you are a believer in Jesus Christ (Believer). Refer to: Hebrews 9:27 “Just as people are destined to die once, and after that to face judgment” What does the ”after that to face judgment” statement mean?