Hebrews 9:27 says, “it is appointed for man to die once, and after that comes judgment.” All people will be judged after they die, which determines where they will spend eternity. Jesus Himself speaks of people either receiving eternal punishment or eternal life (Matthew 25:41-46), but He also makes it clear that the only thing that determines their destination is whether they put their trust in Him alone. John 3:18 says about Jesus, “Whoever believes in him is not condemned, but whoever does not believe is condemned already, because he has not believed in the name of the only Son of God.” Anyone we know will only be condemned by not trusting in Jesus.
For the timing of that judgment, we can look to Luke 16:19-31, which shares with us an account of a rich man who dies and is immediately tormented by fire (v. 23-24) and a poor man who is comforted (v. 25). The passage makes it clear that the rich man wants to change his mind and even convince his family to change their minds, but he can’t (v. 26-27). While this is very sad, it helps us understand that this life is given as an opportunity for people to choose to walk with God. If we choose Him now, we get Him forever. If we don’t choose Him while we live, we will be forever without Him by our own choice, and the place without His presence is a lake of fire created for the devil and his rebellious angels (Matthew 25:41).
If you’ll read Revelation 20:11-15, you’ll see judgment day in action and witness how people are judged for what they’ve done, and the only thing that rescues people is having their name written in the Lamb’s book of life, which we know from John 3 is only by Jesus giving us His own righteousness by faith. His deeds become ours so that we don’t have to be judged for our failings on judgment day!