The sentence “jesus will further return.” is one of the consequential and clue concepts which is implicit in the bible more than 300 times.
In ‘New Testament’ several complete chapters dedicated to christian behest. (Matthew, chapters 24&25 ; Mark, chapter 13, Luke, chapter 21)
Some enchiridions merely endeavor to express this concept’s importance, as well as the book “Johannes’s Apocalypses” which is completely about the apocalypse incidents.

Lot of clue concepts of ‘New Testament’ are not apprehensible, without understanding the concept of Jesus return.