In my experience, most liberal Christians don't dislike the non-religious, although some of them get rather testy about critiques of fundamentalism rubbing off on them. Some of that is understandable, some of it is a function of them not taking enough of a stance against their fundamentalist brethren and getting defensive / uncomfortable about being reminded of that, however obliquely.

But fundamentalist / inerrantist / literalist / evangelical Christians are another matter. MOST (not all) of those see any sort of disagreement or push-back as an existential threat.

Why? Because they aren't able to separate their beliefs from their identity. Their beliefs, to them, ARE their identity. So "attack" the beliefs (and "attack" in their mind need only be, "fail to agree with" or "question" or "doubt" ) and you attack their very existence.

Another, closely related reason is that because they are all about beliefs, they are obsessed with those beliefs being correct -- lest god punish or judge them, or their fellow believers judge them, or their own already substantial self-loathing is made even worse. So if you introduce the slightest doubt or discouraging word about the correctness of their beliefs, it's a source of terrible anxiety.

Lastly, there is no evidential basis for their beliefs and so they have nothing but appeals to popularity, appeals to authority, appeals to ancientness, and such like, to support them. If you're not part of the praise chorus of people who think they are virtuous and right, then they have to expend energy pretending to debate you, or ginning up lame apologetics for their beliefs, and they don't like having to do that.

I actually don't think such people hate unbelievers or doubters so much as they hate unbelievers or doubters who give voice to their unbelief and doubt. Unbelief is one of the worst sins in their book -- arguably THE worst, and the wellspring of all other sins. So there's fear and loathing around that, too.