The Christian scholar William Barclay in his commentary on Revelation quotes another Christian scholar R.H. Charles as saying that the above mentioned passage in Revelation "may not be part of the original book at all" (Revised 1976, volume 2, p. 232). After mentioning the reasons for this, Barclay agrees with Charles by saying:
It is, therefore, by no means impossible that these words are not the words of John but of a later scribe anxious that none should alter the book in the days to come (vol.2, p.232).
But even if that passage is genuine, it does not prohibit a believer from believing also in the Qur'an. Many people misunderstand the passage if they are unaware of the history of the Bible and how it came to be written. They assume that because the book entitled Revelation is the last book in the Bible it must have been the last book from God, and that every later book should be rejected. However, according to many Bible Commentaries such an understanding is wrong. The Abingdon Bible Commentary explains as follows:
The fact that the words happen to come at the end of the English Bible has led sonic to suppose that they applied to the whole Bible itself. This, of course, is not so. As a matter of fact, several New Testament books were written after Revelation (The Abingdon Bible Commentary, 1929, p. 1 398).
As the above quote explains, the book entitled Revelation cannot be the last book from God. The Bible itself contains some books which were written after the book entitled Revelation.
The New World Translation of the Holy Scriptures, shows that four books in the Bible were written after Revelation (Revised edition 1984, p.1 547). Similarly, Asimov's Guide to the Bible shows that Revelation was not the last book of the Bible to be written (vol.2, p.567).
Another book entitled Key)? to the Bible claims that the last book of the Bible was 2 Peter (see vol 3, p. 152). Yet another Christian scholar points out that at least six books in the Bible were written after Revelation (see Reading the New Testament by Pheme Perkins, 1988, pp.2-8). Clearly, then, the passage does not prohibit its believers from accepting later messages from God. In spite of that passage, believers were still able to believe in other books which they included in the Bible.
Every seeker of truth must examine the Qur'an too to see if it really is from God. One who examines the Qur'an will find the following:
1. Fourteen hundred years later, all opponents of the Qur'an have failed to produce a book like the Qur'an. The Qur'an rightly said that they can never do it (see our answer to Question 15).
2. The Qur'an speaks about the future, then the future unfolds exactly the way the Qur'an said it would.
3. The Qur'an describes aspects of history unknown to its contemporaries and confirmed by independent studies (see Question #6).
4. The Qur'an makes statements which no human being could make without knowledge of modern sciences, or prior to the invention of the microscope