Many fundamentalist theists want to reject particular scientific claims because they are not convinced by the available evidence to believe it has been proven true (
Spoiler Alert: Nothing is ever proven absolutely true in science). These theists tend to reference skeptical counter-arguments from apologists and/or so-called "experts" who operate under the notion that divine intervention should be the default position until the evidence they are demanding for a particular scientific claim is provided as proof. The problem with demanding proof for a scientific claim is that science does not function to prove any of its hypotheses are absolutely true, and there are very good reasons for this.
To begin with, science requires its hypotheses to be falsifiable. Every time a qualified and reputable scientist conducts an experiment in a relevant field, there is an opportunity for the results to disprove the corresponding hypothesis. In fact, the exact purpose of every scientific experiment is to try and disprove a proposed explanation. So, what justification do scientists have for not attempting to prove their hypotheses are true? Isn't the primary purpose of evidence collection to prove a claim is true? No, such a perspective on the role of evidence would consistently leave scientists and their conclusions susceptible to
Confirmation Bias. Accordingly, the
Falsifiability criterion has been instituted as a mitigation for the possible influence of confirmation bias.
To understand how the falsifiability criterion secures the unmatched credablity and reliability of all currently accepted scientific theories, it is necessary to explore a little bit of philosophy. Let's begin with the
Problem of Induction. Inductive reasoning is demonstrably unreliable when evaluating a claim because the resulting conclusion doesn't necessarily follow from the supporting evidence. An example of this fact is the inductive argument for the claim that all swans are white. At one point in history, swans had only ever been observed to be white in color. Therefore, it seemed reasonable to inductively infer from the evidence available at the time that all existing swans must be white. But how could the truth of this claim be verified to rule-out the possibility of confirmation bias?
To verify the claim's truth, every individual swan in existence would have to be observed to determine if all are white in color. Obviously, this evidence is not reasonably obtainable. Consequently, the possibility for a different colored swan existing somewhere unobserved could not be reliably ruled-out. So, the truth of the claim that all swans are white turned out to be
Underdetermined by the available evidence. Therefore, the possibility of confirmation bias could not be ruled-out. However, it is important to note that a single observation of a different colored swan would function to reasonably falsify the claim.
As it happened, someone did eventually observe a black swan in Australia. This discovery reasonably demonstrated that the claim, "all swans are white," was a product of confirmation bias after all. So, while it wasn't possible to observe every individual swan in existence at the time to determine the claim's truth value, it was possible to reasonably falsify it. It logically followed from this outcome that falsifiability was a more reliable and justifiable criterion for scientific claims than the verifiability of their truth given the problems of confirmation bias, induction, and underdetermination.
The fact of the matter is that these problems are not unique to science but apply universally. Science may have uniquely solved these problems by implementing the falsifiability criterion for its hypotheses, but nothing seems to logically prohibit this solution from functioning in non-scientific contexts as well. If theists want to reject the solution provided by the falsifiability criterion, then they must provide a justifiable alternate solution to the universal problems of confirmation bias, induction, and underdetermination that equally apply to their religious claims. Otherwise, despite the quantity and quality of the supporting evidence theists might have for their unfalsifiable claims about the supernatural, the unresolved problems of confirmation bias, induction, and underdetermination will provide a reasonable justification to dismiss their corresponding apologetic arguments as logically fallacious.
Meanwhile, the currently accepted falsifiable scientific claims continues to survive all tests designed to try and disprove them. Please note that the acceptance of a scientific claim does not necessarily correspond to any assertions about it being absolutely true. Sure, many science communicators may colloquially refer to various scientific claims as being "proven true," but such phrasing should be understood to mean that those explanations are falsifiable yet have never been disconfirmed by any quanity or quality of evidence discovered to date. Therefore, all arguments rejecting a scientific claim on the grounds that the available evidence is insufficient to prove it is true are fallacious and should be immediately dismissed.
At the same time, any suggestion that some quantity or quality of newly discovered evidence will function to falsify a particular scientific claim should be carefully examined and considered. However, anyone defending a scientific claim must be mindful to identify and expose where intellectual dishonesty exists in the objections they encounter. In all previous circumstances where such invalid objections have been made by duplicitous individuals, the proposed disconfirming evidence turned-out to be either manipulated or misrepresented.