In science, a theory is logical explanation, or a testable model of the manner of interaction of a set of natural phenomena, capable of predicting future occurrences or observations of the same kind, and capable of being tested through experiment.
I’m not saying scientists can’t be religious. I’m saying the scientific method; the most reliable way we have to make sense of the world is inherently irreligious. I find it exasperating when the faithful use their religious experience and testimony as ‘evidence’ that I should take with a level of credibility.
Religions by making pronouncements that are, even if only in principle testable, are entering the area where they have to be prepared for them to be tested logically. Does prayer work? Can all, some or part of the scriptures be true? Can miracles and cures be verified? etc. In answering these questions religion has come up lacking.
Science is full of theories that can never be proven – science does not do proof. A scientific theory explains what the evidence, experiments, observations etc show. If all this couldn't be explained by the theory or if something else came along to better explain it, the theory would be discarded or modified. Rresults are published, peer reviewed and criticism is encouraged.
If the religious are going to treat prayer or any other belief where a god directly affects the material world as evidence, then they should be prepared for sceptical people to see if such claims can withstand scrutiny. Prayer has been tested, including double blind tests but no statically significant results were found for it having any benefit. Actually one test showed those who knew prayers were being said for them faired slightly worse when recovering in hospital. Prayer cannot be repeated to obtain similar results. Prayer simply does not work. It has no more chance of being answered than what could be expected from chance alone.
Of course I have been told by people that prayer does work in their own life. At one time I would have claimed the same. But such claims cannot be verified by the scientific or any other credible method.