I can’t see that sorry. Any rationale that requires an absolute line of reasoning, let alone that contradicts a simple word definition, doesn’t seem logical to me, quite the opposite? Or did you mean that theists might (wrongly) consider it a rational conclusion? That I can see of course, as I’ve seen enough theists make demonstrably irrational assertions, while simultaneously asserting them to be rational.
Ah, I should have read on.
In many cases I’ve noticed theists resort to this final “trump card”, when all else has failed to sway atheists. I’d assumed it was simple sophistry resulting from frustration. It’s only recently I questioned whether they might really believe this fairly common theistic misnomer.