what is the most powerful debate to prove that god does not exsist?

It was not my intention to offend you by using the words "wrote the Qur'an".

It was a shorthand for compiled, put into writing. I thought I had explained it quite well. I am well aware that Muhammad (saw) did not write it down himself.

That's why I looked for his scribes, Zayd ibn Thabit or Ali ibn Abi Talib (people who could read and write).
Those were the ones who codified the holy Qur'an in order to save Muhammad's (saw) revelations from being altered (which inevitably occurs after some time within any oral tradition, especially when there are many different arabic dialects at play).
To their credit, they did this very shortly after the prophet's death to ensure the Qur'an may be persevered in its original form (unlike the christian gospels, which were probably written ≈60-110 years after Jesus's death).

Who were we created by?
Who controls space?
Who controls time?
Who controls gravity?
Who is the supreme being?

Many others...