Unfortunately, being unable to prove something doesn't automatically mean that it's incorrect.
See: Russell's Teapot.
Furthermore, I'm not asking you to prove that God, Jesus, angels etc. don't exist - I'm asking you to back up your assertion that they contradict reality. In other words, how reality would appear different if they did exist.
I looked in the sky for God, Jesus, angles, etc., and didn't see any. This is a proof that they do not exist. They are nowhere to be seen. Any claim that these entities do exist contradicts the reality that they do not.
Yay! So I can use this as a proof against the Antimoon and all that stuff? Really Tom, you are trying to get us to accept that you think if you look for something and can't find it, it proves its non-existence? It very much depends how you look for something though doesn't it? So if invisible kangaroos existed, and you looked for them and couldn't see them, you'd take that as proof they didn't exist and be wrong. I looked in the sky for earthworms and didn't see any, therefore earthworms don't exist.
You're a joke.
If no one has ever seen an invisible kangaroo, that would be evidence that invisible kangaroos do not exist. In terms of germ theory, the anti-moon, etc, people have seen those things. Therefore there is some evidence of their existence. They are not completely invisible to human experience.
Perhaps if you show me where I can look to find God, Jesus, angles, etc., those things can start existing. Until then, they do not exist.