Arguments for God in Quran.

[stretch3172]

Agreed. Just for fun, here's the proof: 

To prove: G (God exists).                                             

1. M (Moral guidance exists) [Assumption]                                                   
2. M↔G [Assumption]
3. G [lines 1-2, Biconditional Elimination].

The second premise is the biggest obstacle. 

Yet it's been proven time and time again.

It's been proven valid, but not sound. Many Christians and Muslims have no problem assuming that all morality is ultimately derived from the will of God. Biblically speaking, that may very well be true, but I'm not convinced that it has to be. Assuming God exists, it may be that He is simply capable of perfectly knowing universal moral axioms/laws, which somehow exist independently from Him in a way similar to mathematical and logical axioms. But if morality is ultimately decided by God, then we would need a separate argument to prove that premise. Otherwise, the soundness can't be shown logically.