Who’s The Author Of The Quran?
Whoever is the author of the Quran is whom we refer to as God. In the Quran itself He claims that He is the Almighty God, and we find no reason for Him to lie to us.
Personally, for me that would only be a question when I know that creatures as complex as humans also exist elsewhere in the universe. In the absence of that, it’s pretty clear that this tiny blue planet is at the dead center of attention for the Creator.
However, one of the three categories of atheists need a good reason to understand why the book cannot be from anyone other than God. So we need to provide something from the book that can be validated independent of the book e g logically or scientifically. If the evidence requires you to believe in the book first then take a verse as an answer this wont help non believers.