Were New Testament Christians reliable witnesses, or were they ignorant fools?

The idea is frequently invoked to justify a pretty sweeping skepticism against the New Testament accounts of Jesus, including the miracles and resurrection. People back then were uneducated rubes who would believe anything. And if so then we really cannot trust what they said, leaving the status of the New Testament in doubt.

Here's what Conversational Atheist said to illustrate the point:

My personal favorite story that helps give an idea of the intense credulity of the time is the one where the town mistakes Paul for Zeus! Paul barely manages to stop the high priest of the Temple of Zeus from offering a sacrifice to Paul/Zeus.

Hmm. Interesting. Let's take a look at the text in question and think about this some more:

8 In Lystra there sat a man who was lame. He had been that way from birth and had never walked. 9 He listened to Paul as he was speaking. Paul looked directly at him, saw that he had faith to be healed 10 and called out, "Stand up on your feet!" At that, the man jumped up and began to walk.

11 When the crowd saw what Paul had done, they shouted in the Lycaonian language, "The gods have come down to us in human form!" 12 Barnabas they called Zeus, and Paul they called Hermes because he was the chief speaker. 13 The priest of Zeus, whose temple was just outside the city, brought bulls and wreaths to the city gates because he and the crowd wanted to offer sacrifices to them. (Acts 14:8-13)

Does this text provide a general example of the credulity of people in biblical times? I mean it does look pretty silly, doesn't it? Ignorant country folk calling Paul and Barnabas Zeus and Hermes?

I'll offer three points by way of response.

First, I would note that the citizens of Lystra only drew their conclusions of divinity when they witnessed a miracle. In light of their background belief in the existence of Zeus and Hermes and this miraculous event, it would seem rational to conclude that Paul and Barnabas were divine. So I don't think this is particularly damaging to their credibility.

Second, let's say the citizens of Lystra were particularly credulous. So what? Does that warrant a general about testimony from the ancient world? Well what if your car broke down in Batesville, Arkansas and some of the population heralded you as the second coming of Christ? Would that experience warrant general scepticism about testimony in the modern world? Who would suggest something so bizarre? Surely not Conversational Atheist?

This brings me to the third point. The real issue here comes in verse 10. Many people today assume that miracles are not possible and thus that the miracle reports are really the key evidence of credulity in the ancient world. Because the ancient world believed in miracles we cannot trust their testimony when it comes to miracles.

But this simply begs the question. We can only decide about the possibilty of true miracle reports when we have first addressed the question of whether there is a God. If there is a God then of course miracles are possible. And thus we cannot conclude a priori that reports ancient or contemporary are unreliable simply because they include reports of the miraculous. We need to investigate the evidence.

This means that Conversational Atheist's attempt to show the incredulity of the New Testament really depends on the assumption that there is no God of the miraculous to begin with. Now what evidence does he have for that?