How so? That precludes the possibility that there are things that Humans simply aren't smart enough to understand, a rather arrogant belief. As for how we "measure" the Q, we can't. That's the whole point.
This is why I and many are skeptical about his claims. It may indeed be in the Q's nature to "seem" vulnerable, such as getting punched by Sisko, while being in complete control of every situation that could ever possibly exist. But how do we measure this? By what laws of logic does the Continuum operate? Simply saying that it's beyond our "puny" minds is a cop-out.
No, the point is that we don't just have to take the Q, or Q specifically, at face value simply because he says so.
The Federation may have advanced medical technology and could indeed make some rather bold claims about it. But if they claimed to be able to restore the dead to life, sure, a primitive people may not have the means to disprove this possibility, but nor would they be compelled to accept it either. The Federation made the claim so it would be up to them to demonstrate that it was true.
What Q is asking us to do is accept that simply because he's big and powerful, that he is the biggest and the most powerful, and to accept it only on faith
. On something that can pretty much never be demonstrated.
Believing that something is all powerful/omnipotent simply because you can't prove that it's not is, quite simply, a leap of faith. It's the cornerstone of theology. That would very well make the Q nothing less than gods to those who believed it (a descriptor Q no doubt has no problems with). Since it doesn't matter what is true
from the perspective of someone who cannot ever be shown that it is or isn't true, I choose to remain deeply skeptical about his supposed omnipotence.
Considering Q is a manipulative, meddlesome, child-like prick with a depraved indifference to suffering (and truth telling), I'm going to keep on believing that he is exaggerating just a tiny bit.