It has depths of meaning, certainly there's the literal one but you are hugely mistaken in saying that there's only as much as u see on the surface. I advise you to stay shut on this topic, thanks
My wording was incorrect, sorry about that.
What I meant was that the Qu'ran is infallible.
What is written in the Qu'ran is the truth, and Islam can never change.
Comparison:
In Christianity, homosexuality has for years been considered a big sin. Not so anymore, at least parts of the Christian Community is accepting homosexuality.
They do so because "Jesus loves everyone", and tolerance and acceptance are key words to these Christians.
And these Christians interprets this to be more important, and even making the Leviticus 18:22 anti-gay phrase "you shall not lie with a man, as one lays with a woman" obsolete (there are plenty of others in the old testament).
This would not have been possible, if the Bible were the direct words of God. Then, Christians would've been bound to be anti-Gay, whether they liked it or not.
In other words: If you think the Qu'ran is wrong in one single issue:, you cannot , you should not , be a Muslim.
You can't "just" believe in Allah, but not in the Qu'ran either, (comparison: lots of Christians claims they believe in God and Jesus but don't believe the Bible).