Revelation 21:1–8 continues the progression of events which came after the end of the tribulation: Christ’s return to earth (Revelation 19:11–16), the defeat and destruction of those who war against Christ (Revelation 19:17–21), the incarceration of Satan (Revelation 20:1–3), the millennial reign of Christ (Revelation 20:4–6), the release of Satan and the nations’ final revolt against God (Revelation 20:7–10), and the great white throne judgment (Revelation 20:11–15). Here we see the creation of the new heaven and the new earth. Upcoming verses describe the New Jerusalem (Revelation 21:9–27).
For a more detailed summary select the link below.
“Revelation 21:8” Bibleref.com
7 He who overcomes, I will give him these things. I will be his God, and he will be my son. 8 But for the cowardly, unbelieving, sinners, abominable, murderers, sexually immoral, sorcerers,a]”>[a] idolaters, and all liars, their part is in the lake that burns with fire and sulfur, which is the second death.”