If any one takes away: this may be translated “Whoever deletes,” or “omits,” or “subtracts.”

The words of the book of this prophecy: Revised Standard Version formally represents the different form and word order of the Greek, but the meaning is the same as in verses 7, 10, 18. See also comments at 1.3.

Take away his share in the tree of life and in the holy city: for the Greek noun translated share, see 20.6, “he who shares in,” meaning “who has a right to participate in”; see also 21.8, “their lot” in a negative sense of having a share of punishment. The meaning of this statement is “take away his right to eat the fruit of the tree of life and to enter the holy city” (see verse 14). Or else, taking the words in a more literal sense, the idea may be that God has given each believer a share of the fruits of the tree of life and a place to live in the new Jerusalem: “God will take away from him his share of the fruits of the tree of life and his place in the holy city.” For the holy city see 21.2, 10.

An alternative translation model for verses 18-19 is:

• I, John, solemnly warn all who hear the reading of the prophetic messages that I have written in this book: if you add anything to them, God will add to your punishment. God will punish you with the seven plagues described in this book. And if you take out anything from the prophetic messages of this book, God will take away from you the blessings described in this book. God will take away your right to eat the fruit of the tree of life and to live in the holy city.

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on The Revelation to John. (UBS Handbook Series). New York: UBS, 1993. For this and other handbooks for translators see here .