God in the Christian concept exists beyond such matters as the material world, cause and effect, logic, science, and all that. No system exists to disprove something that would exist beyond all systems. You could disprove cases where he supposedly did interact with the material world (such as by showing that some event that is claimed to have happened didn’t happen), but that’s the limit of any disproving.
It’s easy enough for those who disbelieve to support their disbelief, though: if God does exist, then where is the proof? Lack of disproving is not proof of existence. Just as you’d need actual proof to disprove the existence of God, you need actual proof to prove God’s existence as well. And all that just about anybody in the world has seen is inference and stories that were already second-hand thousands of years ago.
Besides, it’s not up to those who have not seen any evidence in support of an idea to provide proof. It’s the people who do support an idea who should do so. Imagine what it would be like if you had to disprove the existence of every single faerie tale creature and myth. How would you disprove LaMa’s unicorns? You’d have to check every single square centimeter of the entire Universe simultaneously to do so, and that would be physically impossible (and even then it could be argued that that wouldn’t truly prove anything). So if you’re supposed to believe in something unless it can be disproven, then you’d have to believe in a huge amount of stuff, most of it mutually incompatible.
On the other hand, to prove the existence of unicorns, all that would be needed is for somebody to show one. Quick, simple, and definitive. It should be simple to do, if unicorns do exist.
So while there’s no way to disprove God, it should be possible to prove that He does exist (if He does). Can you provide any such proof?