Revelation is the most Universalist NT book if we understand the "reverse symbology" it contains. For instance: Rev 19:21 "And the rest were killed (converted) by the sword (word) of the rider" . . . or
Rev 14:19 . . . "the great winepress of the wrath (loving correction) of God".
Those two texts describe the same event, but in different symbols. Dying to the flesh is to live for God.
The positive message of the salvation of all in the book of Revelation makes this my favourite book.