The logic of religious conclusions is not—in a sense—incorrect.
*waits for it*
As I am sure many non-believers no doubt let out a pip of laughter at that last statement. I should point out that it is incorrect to snicker at the concept of "religious logic." Of course there is religious logic! They have premises and reasoning which inform their conclusions based on the former. This is what theology and apologetics are.
So we can say that yes, fundamentalists have logic and are simply following scriptures to their logical conclusions. I would even go so far as to say that fundamentalist religiosity is not internally illogical and is actually completely logical based on the premise of scripture. The fundamentalist closely follow the premises that scriptures dictate.*
Conversely, liberal theologies have the problem of being internally illogical and inconsistent. They are the perfect example of cherry-picking. To defend portions of scripture as “Truth” while omitting entire passages or books as irrelevant, out-of-date, or just too horrific…well…it has no logical consistency.
By stating this I am not conceding anything nor am I defending it. Too often people have an incorrect view of what logic is, as if proper logic ensures a correct conclusion. It does not. Logic is the process of getting from point A to point B (or C, or D, etc.) via valid reasoning, when A is “given.” None of this is a defense of religion, religious belief, or apologetics. What it is, however, is a condemnation of the premises of religion. It is the premises of supernaturalism and theism that are unsupported and absurd. I have no reluctance in stating that it is wrong, but it still can be logical given “the given.”
*If it is indeed possible to follow scripture perfectly (due to the contradictions) one would be labeled a monster and ultimately incarcerated. What does that say about scripture?