There are a lot of reasons for doubting that the Qur’an is inspired.
-It contradicts known facts of science. For example, it teaches that the sun actually descends down into a muddy spring on the earth (Surah 18:86). You could get away with a statement like that in certain parts of the world in the seventh century. Obviously, today, we know that the sun is actually on a circuit through space.
-The Qur’an contradicts known facts of history. For example, it denies that Jesus of Nazareth was crucified on a cross (Surah 4:157), something that has been substantiated not only by the Bible but also by extrabiblical sources, such as the Jewish Talmud and Flavius Josephus.
-The Qur’an has multiple internal inconsistencies.
There are no good reasons to accept the Qur’an as inspired Scripture. The most popular evidence that Muslims try to give for the divine inspiration of the Qur’an is its literary beauty, but this is a highly questionable means of testing a document for divine inspiration. What would stop us from believing that Shakespeare’s writings were also divinely inspired? After examining these things, it would be safe to conclude that the Qur’an is not an inspired book.