William Lane Craig diagnosed.

[Jehanne]

Dr. Craig suffers from the Dunning–Kruger effect:

https://en.wikipedia.org/wiki/Dunning%E2...ger_effect

This cognitive bias is when a, "relatively unskilled persons suffer illusory superiority, mistakenly assessing their ability to be much higher than it really is."

First, an example of Dunning Kruger syndrome, after which I'll disagree with your diagnosis of Craig. 

I knew this guy who worked as a carpet cleaner.

It's all relative, of course.  Compare yourself to that carpet cleaner and then do the same comparison between Craig and someone like Sean Carroll.  With respect to the latter, he is a professor of theoretical physics at the California Institute of Technology.  Craig was a communications major who went onto Bible college for his "graduate" studies.  Just do a comparison on the admission rates of Cal Tech and any Bible college.  Relative speaking, Craig is "unskilled".