A strawman argument is basically arguing against something that’s easier to debunk than what your opponent actually said.
For example, John W. Loftus calls this one of the most asinine claims made by Christians:
It’s claimed that people like Dawkins, or Hitchens, or Harris don’t know enough to reject Christianity. How much should a person know about a religion or the various branches of it in order to reject it? Really. I’d like to know. (source)
If that’s the way that Christians actually articulate this objection, then yes, that’s asinine! However, I don’t think that anyone is saying this in spirit, even if they are in words.
What I think they are trying to get across is that Richard Dawkins, Christopher Hitchens, and Sam Harris don’t know enough about Christianity to adequately criticize it. Dawkins is the prime example–one of the arguments central to The God Delusion is the second grade retort, “Well, who made God then?” That’s pretty sad coming from a man of Dawkins’s caliber. He’s a decorated scholar and an eminent scientist; you’d think he’d realize that philosophy has long progressed past that point.
It’s undeniable learned scholars such as Dawkins venture into territory which they are not as familiar with as they should be before taking the plunge. Maybe they know enough to confidently reject Christianity–they probably know at least as much about Christianity as I do about Mormonism, Jehovah’s Witnesses, and Roman Catholicism and I reject all of those.
However, before I try to criticize something, I attempt to become familiar with what it actually argues. These guys don’t. They stick to surface-level arguments and barely take a nick out of those. Much of what they do is argue by outrage, which is the direct opposite of the rational inquiry that they always call for.
I have no doubt that, in a slip of many tongues, Christians have probably said that the New Atheists don’t know enough about Christianity to reject it. However, that isn’t correct. These men don’t know enough about it to criticize it. I have a feeling that, while the formulation may have been incorrect, the articles by my fellow apologists would clearly explain that these men have seriously misplaced criticisms due to profound misunderstanding of basic Christian doctrines, theology, or arguments.
And that makes this a strawman argument from John Loftus.