What one thing would disprove Christianity to you?

[Undeceived]

Exactly. The bias is to withhold judgment until a natural solution is found.

So, scientists are bias because in the absence of any understanding of natural mechanisms they refuse to entertain an untestable, supernatural hypothesis? I think you are confusing bias with intellectual integrity, which is that the lack of evidence for one hypothesis does not strengthen the case for another. Each must meet the burden of proof, and the fact that our current body of scientific knowledge lacks a natural explanation does not get the supernatural explanation any closer to meeting this burden. Therefore, judgement must be withheld until an hypothesis can meet this burden, which every supernatural claim has failed to do.

Science does what science does. It has its place. But when questions arise that science cannot technically answer, why not go to the realm of philosophy that can?