I did some research and found that, as far as I can tell, Robert Price is the only important scholar who claims that this is an interpolation. I happen to know Price personally, as we sponsored a debate with him as the opponent. We treated Price very respectfully and gave him a stage to voice his opinion, but, to be honest, I found myself struggling to respect Price, either personally or as a scholar.. When an angry young man published very disrespectful comments about me personally on line, Price cheered him on, whereas even my atheist friends realized how biased and unfounded his this angry young student’s statements were. Price takes stands that virtually all other scholars, even skeptics and atheists refuse to embrace. It appears that he reaches conclusions that are in concert with his negative attitude toward Christianity, regardless of whether facts back up those positions.
His stand on 1 Corinthians 15:3-11 falls into this category. Like I said, as far as I can tell from some admittedly quick research. Price is the only one out there making this claim. Here is why. There is literally zero manuscript evidence to support this claim. As a rule, when responsible scholars claim that a particular phrase or section of scripture is an interpolation–added material by an advocate of a particular doctrine–they do so because there is at least some manuscript evidence to support the conclusion. From what I can tell, all of Price’s arguments are of this sort: They are arguments that it is not logical that Paul would say this, or it is not likely that he would say this. Such arguments are based on logic, but not on evidence. Besides, when I looked at his arguments I found myself saying “that is your argument?” These arguments are not strong ones at all! They are of the sort such as this: In such and such New Testament writing, when they talk about this, they do not mention that person but Paul does mention, so this is probably made up or he makes the reverse argument–that he does not mention someone that another writer does, so this cannot be by Paul. I find these arguments to be extremely weak, but please feel free to look at them for yourself at the web site above.
Here is the bottom line. This is an argument with literally no evidence to support it. I am not a big fan of burden-of-proof arguments generally but if someone wants to propose that a particular passage of scripture is an interpolation, then the burden of proof is on the one who claims that there was an interpolation. If you claim that I visited North Dakota last August, the burden of proof in this case would be on you. I would not have to prove that I did not go there. I cannot prove that this passage is nott an interpolation. It is not possible to “prove” such a negative, but, given that Price has no evidence, I conclude that is claim is coming from his world view, not because he is correct.
So, Price offers no evidence whatsoever for his claim. Here is the deal. He does not believe that Jesus was even a real person, never mind that he was resurrected from the dead. The reason Price supposedly believes that this is an interpolation is that he does not like the fact that Paul is telling us here that Jesus was raised from the dead and that there were hundreds of eye-witnesses. Not liking something is not a good reason to not believe in it. You can safely completely dismiss this argument from Robert Price.