Living gods don’t need ancient poorly attested miracles as evidence of their creeds. Living gods can work living miracles. The reliance, therefore, on long dead tales to support the existence of living gods, is a fallacy of the first order. It would only be necessary in a world without gods. Which is why we can know such is the world we live in.
i) There's a grain of truth to his statement. However, a chronic weakness of Carrier is that he's addicted to hyperbole, so his statement is, at best, a half-truth.
ii) I myself have said that when it comes to the argument from miracles, many Christian apologists are stuck in a rut. There's an overemphasis on the Resurrection, and overemphasis on ancient documentary evidence for miracles in the distant past. There's nothing wrong with including that in your case for miracles. But it should be augmented by evidence for modern miracles.
iii) I don't agree that biblical miracles are poorly attested.
iv) A living God is a God who acts in the past as well as the present and the future. If he performs miracles, then he performs them in the past as well as the present. So there's nothing sneaky or untoward about appealing to past miracles, anymore than we appeal to past evidence for past events generally.
v) Ancient history is Carrier's specialty, so it's duplicitous for him to automatically discount "long dead tales".
If he performed miracles anciently, he should be doing so presently, indeed all the more, as the population in need of them is now a thousand times in size—so miracles should be thousands of times more frequent.
i) It may well be the case that the number of miracles has increased over time. But according to Scripture, God never performed miracles just to meet the need for a miracle. There was never a miracle for every problem that only a miracle could solve. Jesus healed people who came to him. He healed people who were brought to him, or brought to his attention. But the Gospels don't record him healing people in general. In the OT, God doesn't perform miracles for pagans generally. Indeed, God doesn't perform miracles for individual Jews generally. In Scripture, God never performs a miracle for everyone in need. Not remotely.
ii) For that matter, not all biblical miracles are beneficial. Some are quite destructive. They may help some humans by harming others.
You can explain your way out of that with a bunch of made-up “assumptions” about how God would behave differently than any other person in the same circumstances; but such “gerrymandering” your theory would only reduce the probability of that God existing, not rescue it from disproof as you might irrationally have thought.
Actually, there's a good reason why God would behave differently than any other person in the same circumstances. Unlike shortsighted human agents, God has foreknowledge and counterfactual knowledge. Just about every miracle has a snowball effect. Every miracle alters the future. So the miracles that God performs must be consistent with his plan for world history. Performing additional miracles results in a different world history.
What remains is scenario one: God performed tons of miracles in antiquity—parted seas, rained fire from heaven, turned people into salt, transformed sticks into snakes, raised the dead, turned water into wine, became incarnate, flew into space, mystically murdered thousands of pigs, erased the sun. On and on. But now he doesn’t.
i) Yet another example of Carrier's penchant for hyperbole. Despite the fact that the Bible is a very long book, the number of recorded miracles is about 150+. So the ratio of miracles to the span of Bible history and the number of individuals is quite scant, percentage-wise.
ii) The sun was never erased.
iii) Jesus never flew into outer space. At the Ascension he levitated, and was then enveloped by the Shekinah.
iv) It isn't possible to murder pigs. And Jesus didn't consign thousands of pigs to drowning. It was just a herd of domesticated pigs. 20? 50?
iii) The Red Sea crossing happened once. The destruction of Sodom and Gomorrah happened once. The fate of Lot's wife was a one-time event. Jesus raised three people from the dead.
And that’s why miracles are never believable. If the world were the sort of place miracles really occurred, we’d have tons of solid evidence of that fact by now. Yet we have accumulated no solid evidence of it. None.
That raises a nest of epistemological issues:
i) Miracles aren't like tree rings, where you have permanent cumulative evidence. Rather, miracles are more like fruit trees producing cumulative perishable fruit. Every year the tree bears fruit. Over the course of a productive lifetime, it may bear a lot of fruit. But while there's a cumulative total, that's not the same thing as cumulative evidence, because most of the fruit perishes. It rots or is eaten. There's no permanent record of the total produce. Like so many other things, miracles are cumulative, but the direct evidence is usually ephemeral rather than enduring.
ii) Take someone who undergoes miraculous healing. In a sense, that individual is evidence for a miracle. Yet the evidence may be indirect. It may not be apparent that the individual ever had a medical condition requiring a miraculous cure. Just looking at them, you can't tell. So you'd need some before and after evidence to provide a basis of comparison.
iii) In addition, the individual will eventually die, so in that sense the evidence will die with them.
iv) Most miracles, if they happen, are basically private underreported affairs. They happen to nobodies. They are known to handful of confidants.
v) Some people are reluctant to talk about uncanny experiences they had for fear people will say they are crazy. Indeed, the sneering attitude of atheists like Carrier is a disincentive. People don't like to be ridiculed, so they're selective about who they share things with.
vi) Because miracles are discontinuous with the past, they don't leave a long chain of evidence. The trail goes cold. There's the situation before the miracle. Then the miracle marks a new start. A reset. So we're limited in our ability to trace a miracle, unlike linear cause and event which extend back indefinitely to antecedent conditions leading up to a particular event as well conditions leading away from the event.