To address the point about the material nature of the human mind, and human existance, I would like you to consider this: in about 5 billion years, the star that is at the center of our solar system, the Sun, will have burned up most the hydrogen that it contained, and released it as heat and radiation into space. At that point, the gravitational forces that currently hold the Sun together, will have diminished, and will not be enough to counteract the repulsive forces of the heat inside the Sun that wants to push the whole thing apart. The Sun will turn into what is called a Red Giant. It will expand in size to such an extent that it will be bigger than the radius of the Earth's orbit. Obviously the Earth will be vaporized and engulfed into the Sun. At some point the Sun will explode, and a Super Nova event will be created. The Sun, all the Planets, and everything in them and on them, will once again turn into interstellar gas and dust.
If by that time, humans have not figured out how to get off of the Earth, and colonize other Solar systems, what do you think will have been the "meaning" and significance of human existance on the Earth ?
The answer is NONE. At least that's the best answer that is available based on any current evidence. Therefore that is the answer that we must adopt for now.
So, "what value is there to Persian history or the survival of a separate Iranian identity" ? The answer is none, ONLY IF all national borders were eliminated, and all resources on the Earth were shared equally among all humans. If the entire Earth becomes one country, then nationalism won't matter. There will still be unique local cultures, like there are in any country today, but as a whole, all of humanity will exist as one nation.
If all humans share resources, and live and let live, then any human can be certain that "he and his family can survive decently". But when a group of people who call themselves "iraqi", attack another group of people who call themselves "Irani", in order to take over their resources, and to rule over them dictatorially, then the "Irani" have no choice but to collectively strengthen their unity and unique identity, in order to protect themselves, and the resources that they have available to them, because otherwise nobody else will feel sorry for them and help them ensure that "he and his family can survive decently".
When akhoonds take over Iran, and take all the resources and riches of the country under their own control, and they get fat and rich, while the Iranian people starve and cannot ensure that "he and his family can survive decently", then the Iranian people must strengthen their national unity and pride in their unique heritage, and fight against the akhoonds, and their ideology of arab imperialism, that is designed so that the akhoonds and islamists can ensure that "he and his family can survive decently", while the Iranian people cannot. That is what the arab invaders of Iran did, and that is what the akhoonds are doing today.
So, will any of this matter in 5 billion years when the Sun explodes ? NO. But we do not live in time spans of billions of years. We live at most a hundred or so years. Our evolutionary instinct leads us to fight for our survival so that we can procreate, and ensure the safety and longevity of our children.
Is there any final "meaning" to that ? No. What is the basis for the assumption that there has to be any meaning ? None.
So, the Universe will just go on despite what we do or don't do. So just live and let live, and "don't worry, be happy". Drink your wine, love your lover, enjoy your life while you can. So said Khayyam.
p.s. I don't quite say that "there is no non-material spiritual component or dimension to the mind of man". I have said that there is no Supernatural basis for the spiritual aspect of the human mind. Meaning that there is no such thing as "soul" or "ghost" or "life after death". But the human mind does have a spiritual aspect. The spiritual aspect of the human mind arises out of the underlying lower-level mechanisms, ie, the biophysical/chemical. The spiritual aspect of the human mind is that which I called the "collective human consciousness" in another article. It is that part of our mind that is based on our interactions with other humans, out of our culture, our history, art, literature, science, etc. Our rules of Morality and ethics, and "spiritual" existance come out of that non-material "collective human conscioiusness".