What one thing would disprove Christianity to you?

[Ryantology]

The quantum vacuum is not "nothing" like you say but a  wave of fluctuating energy that's controlled by physical laws.

Whatever there was before the Big Bang is almost certainly not "nothing" like you say it is. There was almost certainly stuff going on 'before' the Big Bang, but we don't yet know how to understand it. This ignorance is right where you put God, and you do so based on an assumption which is almost certainly incorrect.

Besides, any scientist will tell you that the laws and properties of the quantum vacuum  is unknown.

Any scientist would tell you that our laws of physics break down once you get too close to the instant of the Big Bang, but no scientist would claim that laws and properties of all kinds were non-existent before that instant.