If God was interested in proving something with miracles here are 10 things he needs to do better:
1) The claim that a violation of the laws of nature has occurred should not be evaluated or investigated by committed, zealous believers. Humans have an uncanny knack for finding what they are looking for. The virtue of double blind testing procedures in science is that they help us prevent undue influence by wishful thinking, conflicts of interest, hedging, confirmation bias, and sloppy thinking. Many people claim that there are miracles happening on a regular basis now. It would be a relatively easy matter to have an independent panel of objective evaluators, doctors in the case of a healing miracle, examine just the evidence before and after an alleged healing without any leading or suggestive information about what they are looking for. Just show them the X rays, or the diagnoses, or the CAT scans before and after someone is alleged to have been healed of a brain tumor, for example.
2) In general, small samples of information are less trustworthy. The more evidence that can be gathered the better. If a miracle were to occur, all other things being equal, we would have better evidence if there are more people who attest to it. A few emotional believers with a great deal of investment in the cause of the miracle claim are not as reliable (or not reliable at all) as a large group of diverse, autonomous people. If God has the goal of proving his existence through miracles, he’d need to make them evident to a great many, well-educated, skeptical minded people who do not already believe.
3) The larger scale a miracle is, the greater the possibility that it can be corroborated, confirmed, cross-checked, and witnessed. A small miracle—a spiritual leader making a golden ring appear in his palm (which is an old magician’s trick)—is going to be more difficult to confirm, more likely to be faked, and less indicative of some real violation of the laws of nature than a large one. With small miracles, the rest of us are morely likely to get hearsay, anecdotal evidence, conflicting stories, and poor transmission of the information. A miracle that appears to everyone could be vastly more effective. And surely an omnipotent God, or even just a very powerful God would be up to the bigger task.
4) The power of suggestion, social pressure, and peer expectation can be very influential in getting people to believe that something special or extraordinary has happened. Countless psychological studies have shown that it takes very little prompting and only slight suggestions to get people to fabricate stories, deny what they have seen with their own eyes, and come to genuinely believe something a mistake. Any miracle claim is going to be up against this psychological background that will create challenges to its authenticity.
5) Stage magicians have devised ways, through entirely natural means of trickery, to perform feats that are stunning for what they appear to be. They make large objects like cars disappear and reappear. They make people disappear and reappear. They appear to be able to levitate, walk on water, and transport from one location to another instantly. The ability of con artists and performers to do these tricks casts substantial doubts on any alleged miracle that resembles them. Wouldn’t it be perverse of God to bring about a real miracle, but it was the sort of thing that is easily duplicated by a teenager with a magic kit or a magic how-to book, and thereby completely obscure its significance and occurrence?
6) For the miracles we have been confronted with in religious history, having all power and all knowledge might be sufficient conditions for performing them, but they are not necessary. That is, for alleged miracles like healings, levitations, resurrections, making objects appear and reappear, and so on, it would appear that an all-powerful and an all-knowing being could be capable of doing them. But having those properties are not necessary. All that would be necessary to resurrect someone from the dead, for instance, would be just enough power to perform that act (provided it wasn’t faked or mistaken altogether). The occurrence of a miracle by itself, therefore, isn’t evidence for an all-powerful, all-knowing being. It would merely be consistent with such a being’s existence. You wouldn’t want to convict a murder suspect on the grounds that he was in town the night of the murder, would you, since that evidence is consistent with his committing the murder. You were in town that night too. So God’s got a big challenge trying to convince anyone of his existence with miracles. It looks like miracles simply aren’t up to the task.
7) Events that are merely fortuitous for the person considering them, like having a baby, or surviving a car wreck (while many babies are still born, and many other people die in car wrecks), even if they really are the result of God’s violating the laws of nature, just aren’t going to be convincing to anyone who thinks about it very much. These sorts of events don’t look special at all when viewed from a distance. In fact, they appear to be completely predictable and ordinary—every day there will be some people who will survive car wrecks, especially with seatbelts and airbags, and every day there are babies born, especially when people have unprotected sex. Couldn’t I throw a ball up into the air and just as well claim that its coming down is a result of my divine powers and is evidence of my miraculous powers? If it was going to happen anyway, can’t everyone equally claim credit for it, and doesn’t that show that no one gets credit for it as a miracle?
8) Powerful feelings of awe, religious significance, excitement, and enthusiasm themselves are not indicators that something special has happened in the world. We have too many examples of cases where people got very worked up over things that turned out to be mistakes, deceptions, or just insignificant events. Recall that eclipses have been treated in history as indicators of profound supernatural significance. Presumably, God would have the ability to do something more than induce such feelings in people, and he’d know how much those feelings cloud the truth.
9) As the people living in the Iron Age saw it, the world was infused with magical and supernatural events. Their minds and lives must have been overrun with spooks, spirits, supernatural forces, mysteries, and frightening possibilities. Virtually none of the facts about nature that you take for granted were a part of their knowledge base. They didn’t know that such a thing as oxygen exists, they didn’t know that infections are caused by viruses, they didn’t know that it gets dark at night because the earth is turning, they didn’t know what made water boil, and they didn’t know that there are no evil demons. The vast majority of them did not know how to read or write. The average life expectancy was 20-30 years because of their staggering ignorance of medical science and basic hygiene and public sanitation.
If you were God and you were going to pick an audience with the intention of proving your existence and communicating your desires, you almost could not find a more gullible, easily impressed, and more ignorant group. It would take surprisingly little to completely stun them—a toaster would appear to be a wondrous, and miraculous artifact from heaven.10) The placebo effect is well-documented in human beings. When they have the expectation that they are getting treated for a medical problem, the expectation itself has a substantial effect on their state and their reporting of their state. A minimum requirement for even the most modest over-the-counter cold medicine is that it must demonstrate effectiveness significantly beyond the placebo effect level. If it does not, the FDA will not allow manufacturers to claim any real capacity to treat illness. The effects felt in many putative spiritual cures, alternative medical therapies, faith healings, and alleged miracles are undoubtedly the placebo effect. If you’re God and you’re performing miracles, you need to do better than that. And presumably, you’d have the power, the knowledge, and the will to do so.
Conclusion: As far as I know, not a single religious miracle in all of recorded human history satisfies even a single one of these modest, reasonable, and obvious suggestions. Yet they are the sort of requirements that even 14 year-old high school science student understands and learns how to investigate empirically. How can it be that the most powerful, most knowing, and morally perfect supernatural being in the universe can’t seem to do any better? Answer: there isn’t one.