Imagine if you wrote a book on Electrical Engineering and a primary school boy who has not read the book starts telling people that the book is false and that it is rubbish and that it contains lies...What would you think?
The boy is a tad unwise right? Even if he is a genius, he has not read your book so how does he know what he is claiming?
So also, you are being unwise when you claim God's books are lies without reading them.
Imagine if Bill Gates wrote a book about how to be rich and a poor man who has not read the book says that the book is rubbish and that Bill Gates is lying. What would you think?
The author of the Quran is not Bill Gates, it is God. Imagine what will happen to you if you are wrong.
Just read the Quran.