Witness testimony is evidence and if the witness witnessed the event in question, it is direct evidence, the strongest kind of evidence. But witnesses can lie, witnesses can distort the truth and witnesses can be biased. That’s why we have cross examination in our court system to examine the witness and make sure their testimony is not corrupted. The testimony of religious people giving evidence in court about claiming to have witnessed a miracle, would be torn apart by even an amateur lawyer, right? They might as well have “Biased witness” stamped on their forehead, right?