The term John uses appears numerous times throughout the New Testament to describe the notion of going, going away, departing
(Luke 1:23, Luke 1:38; Luke 2:15; Luke 7:24, etc.). The picture of going, departing recalls what John described in Revelation 20:11: “From his presence earth and sky [lit., heaven] fled away.” Now that the way things were has disappeared, the opportunity opens up for the Lord to fashion a new heaven and new earth reflecting the blessed effects of Christ’s atoning work. Note: as this is the book of Revelation, we are not meant to take earth’s and heaven’s departing literally. We need to grasp that the way things were has vanished.
1 Then I saw a new heaven and a new earth, for the first heaven and the first earth had passed away, and the sea was no more.