I genuinely believe that Christians typically outperform atheists in formal debate. William Lane Craig almost never loses. The same is true of other Christians. But two performances I've recently heard I score as clear atheist victories. I regard them as among the best performances I've ever heard from atheists in formal debate. These are Paul Draper vs William Lane Craig on the existence of God, and one I heard more recently, Arif Ahmed vs Gary Habermas on the resurrection of Jesus.
Both Ahmed and Draper use a similar tactic that I found to be completely disarming towards their Christian opponents. Rather than overstating their case by arguing that God does not existent or that Jesus did not rise they focus on showing that it is not reasonable to believe either proposition by using illustrations and speaking in terms of probabilities. I will here outline Ahmed's arguments to show how this was done.
Ahmed offered three arguments as follows:
Imagine you have 4 independent temperature sensing devices measuring the temperature of water in a bucket. Suppose they indicate 10°C. You place your finger in the bucket and the water feels quite cool. You assume the temperature reading is accurate.
Imagine instead that the temperature indicates 30°C. You find that to be surprising based upon the way the water feels to your finger, but you might again likewise conclude that the readings are accurate.
Now imagine that all 4 of the measuring devices read 600°C. Would you believe the temperature readings? No. Why not? Because water has never been observed to be 600°C at atmospheric conditions in a liquid state. On the other hand multiple independent witnesses have been observed to be in error. Ahmed cited a case study of such an incident involving multiple witnesses, all of whom were well educated, reasonable people.
Bodies that have been dead for 3 days have never been observed to come back to life. Solid bodies have never been observed to pass through solid rock. Granting that we have eyewitness testimony about Jesus (which most skeptics don't believe anyway) the rational person still rejects belief in resurrection.
Suppose an event has been witnessed that has no current plausible naturalistic explanations. In that case, is it reasonable to assume a miraculous explanation? No. Why? Because in many cases currently unexplained phenomenon were later able to be explained naturally due to knew discoveries or new unearthed facts. For instance regarding meteorites, a man no less enlightened than Thomas Jefferson said that he would sooner believe a witness was lying than believe somethings so preposterous as the claim that rocks fall from the sky. Lightening was thought to be supernatural for a time, but subsequently Benjamin Franklin's showed that it was just a form of electricity. Many other examples could be produced. Time and again events thought to have a supernatural origin at the time have subsequently been shown to have natural causes. A person is justified in thinking similarly with regards to the resurrection in the event he has no naturalistic explanation.
This argument takes Argument 2 to its most extreme. Let's imagine that not only are there no current naturalistic explanations of the resurrection, but in addition the Christian has proved that no conceivable future naturalistic explanation could ever explain the known facts. There's no possible way for the Christian to prove this, but let's imagine that he did. We still should not believe in the miracle of the resurrection. Here's why.
We are being asked to believe that a supernatural event has occurred. We're told to believe it for a variety of reasons, such as the fact that a risen Jesus appeared to 500 people at one time. We're told that 500 people cannot have a collective hallucination. But why should we believe that? Because we have no experience with such a phenomenon.
But we're being asked to believe that a man dead for 3 days has come alive. We're being asked to believe that a solid body can pass through rock. We have no experience with that either. But these are permissible, says the Christian, because we're invoking a miracle here. But if invoking miracles is permissible, then aren't there many other possible explanations for the data. Jesus appeared to 500 and people don't normally have a collective hallucination. Unless a miracle occurred. What if they had a supernatural mass hallucination? What if God replaced the dead Jesus with a copycat version? What if the devil impersonated Jesus after his death to trick us into thinking that he is alive? Once we permit miraculous explanations, how do we adjudicate between competing miraculous explanations? What is the justification for preferring one to the other?
The temptation from skeptics, myself included, is to debate Christians on their own terms. I don't think we have eyewitness testimony regarding Jesus. I think alternative explanations explain the data better than the miraculous explanations. So I want to challenge the Christian on these points and show these things. So we get into reliability, errors in the Bible, markers of fiction and legend, etc. Around and around we go. But at the end of the day I've sort of thought that the very nature of the claim coupled with our experience makes the claim unknowable. So even if I were wrong that the Jesus story makes great sense as legend, this doesn't make Christianity reasonable. Every evidential claim that Habermas threw at Ahmed just didn't stick in the face of his arguments. It doesn't matter that the majority of critical scholars think the tomb was empty. See arguments 2 and 3. It doesn't matter that people are dying for this belief. None of that can overturn the common sense arguments that Ahmed presented.
Habermas clearly struggled in the face of these arguments. He replied by bringing up Near Death Experiences to show that these indicate God, which if true would alter the initial implausibility claim that Ahmed is basing his arguments upon. With regards to argument 3 he claimed that Ahmed's example of appearances being miraculous would require more miracles since there were multiple appearances, so this would seem less plausible. Otherwise he was somewhat muddled. More than one questioner from the audience asked Habermas to simply tell us which of Ahmed's premises he denied. Ahmed had provided his arguments on paper in syllogistic form, numbered, so that Habermas could respond clearly. Habermas initially didn't answer. Finally the last questioner again asked Habermas to identify the premises he denied, and at that point he did identify them, but no discussion was possible about his denial at that point.
The emphasis from Ahmed is on the initial implausibility of the claim of resurrection. This is all very familiar to those of us familiar with Bayesian analysis, but Ahmed has couched the concepts in non-mathematical terms that are very accessible to the average person. Ahmed's thinking is also very linear and intelligible. Contrast this with Habermas. To me it seemed Habermas was just way out classed in this one. Which is not to take anything away from Habermas. He's an intelligent person. I just though Ahmed was outstanding.