Well, by lacking "such an ability" (to know), do you mean everything? Or are you restricting to only certain topics, like gods and ultimate realities?
Yes, the later. We can document and prove that I can reliably know whether there is orange juice in my refrigerator. I'm not interested in turning that in to some grand philosophical question.
So the question, to me, then becomes a little different. If you assert that there is no possibility of knowing about the existence of gods, then I can only conclude that is because, if they exist, they can have no effect whatever upon us.
I assert that at the present time there is no evidence that we are in a position to come to conclusions on topics of this scale. As example, we also currently have not the slightest idea whether there is one universe, or 17 trillion universes.
That said, apologies, but your logic is sloppy, and seems to be driven by the conclusion you want to reach. Until recently we had no way of knowing about gamma rays and all kinds of things like that etc, but they still have an effect on us. Why couldn't gods fall in to this huge class of phenomena?
It is clear, in principle at least, that if there were an effect attributable to gods and only to gods, then that effect would be detectable (otherwise, how can it be an "effect?").
No, that's not clear at all. Why do you assume the human mind would be capable of detecting and analyzing "the hand of god"?
And in that case, again at least in principle, it could be studied and possibly learned about.
I agree it might someday be possible.
In the absence of any such effect from which we might discover at least some small hint, then, I propose that the existence of gods is utterly irrelevant, along with the existence of anything else which can have no possible noticeable effect.
If it's utterly irrelevant, why are you, me and billions of other folks unable to let go of the subject? Our interest is a well documented hard fact. It could also be a fact that this question is the biggest cultural event in human history.
So, let's start from the facts. Many of us, including you, are incurably interested. I'm not prejudging in any way what it is we are interested in, only stating the obvious point that we are interested in a concept generally labeled god.
To me, the relevant question is...
Do we wish to continue pursuing our interest in the same way we've always pursued it, in the hopes that doing the same thing over and over again will somehow lead to different results?
That is, do we wish to align our actions with the definition of stupidity?
So all right, you win. Feel better now? Do you have a service for these sorts of things?
You've been attending that service for months now.

And do I feel better? NO! Agreeing with me is the only secret weapon that can defeat me, as my wife has proven in 30 years of marriage. So don't tell anybody! But, I'm not really too worried in your case, because....
But I will still not be worrying about this thing which cannot impact upon me in the slightest possible way.
You'll be back to your beliefs in no time flat.
Here's the deal EH. You don't know if gods exist, nor do you know whether they have impact upon you or not. We simply do not know. Our ignorance is the one hard fact at the heart of all this.
So if you wish to conduct an investigation based upon facts, upon what we do know, our ignorance is where we should begin.
Face it, accept it, work with it. Deal with reality, instead of our fantasy imaginary knowings.
It's an interesting thing to consider, however, that at least some few of the billions of words exchanged around the world on this topic have had some small effect.
Ok, I agree.