Stupid things religious people say

[Ravenshire]

And, just like Christians and their Bible, Muslims will insist (usually at the top of their voice) that there are NO contradictions in the Quran, all evidence to the contrary.

Boru

Even if there weren't contradictions in the quran, it would not prove anything, since the Quran had one single author, unlike the bible which is many books collected into one. It is not that hard not contradict yourself when you are the one single author.

Even given @BrianSoddingBoru4's explaination above, modern authors, even with all the tools available to them, manage to contradict themselves all the time. If modern authors working with far more effective tools can't avoid it, why would you think it easy for an ancient author working before reliable paper production?