Expositor's Bible Commentary Commentary Revelation 22:18

"I testify unto every man that heareth the words of the prophecy of this book, if any man shall add unto them, God shall add unto him the plagues which are written in this book:" — Revelation 22:18 (ASV)

These verses should not be taken as a warning against adding anything to the Bible. They are primarily a strong warning to false prophets not to alter the sense of John’s prophecy in this book, either textually or in its moral and theological teaching (cf. 1 Corinthians 16:22). So severe is the danger he is warning against that John says that those who teach contrary to the message of Revelation will not only forfeit any right to salvation in the Holy City but will have visited on them the divine judgments (“plagues”) inflicted on the beast worshipers.