I'll give these authors this: I've seen more clueless apologists than them. They go in for one-line refutations (There are no absolutes? Is that ABSOLUTELY true?) instead of really engaging (and who says something like that in the first place these days?); but one of them is a real theologian, and is aware of the rudiments of logic. I think they dismiss Hume and Kant too easily (The statement that we can only know what can be logically reasoned or empirically verified is not itself arrived at by logic or empricism...I'd say it's inductively valid), and I think that will be their fatal flaw: they're addicted to 'gotcha' arguments. What would they say to someone who says 'the only absolute truth is that there are no absolute truths other than this one'? I don't think they have any more ammo after that first cheap shot.
I'm not anti-Christian. I'm anti-stupid.