No Coming, No Going
Buddhas or bodhisattvas, enlightened ones, don't die. They have seen to the heart of existence, of being, of reality, so how can they die? Enlightened ones don't confuse natural, organic metabolizing with life, or living, or truth, or reality.
Imagine an enlightened person, perhaps you've been fortunate to know one personally. Imagine them dead, having died, maybe cremated, and imagine their skull, holding their skull in your hands. Is this the enlightened person that you knew?
So you have their skull, their actual skeleton, and you attach layers and layers of organic material onto it, muscles, tissue, ligaments, organs, systems, and you put them into metabolic movement, and you have biology, life. Not uncommon, we all share this biology and in principle this is extended to all life metabolizing on this planet.
Add consciousness, intelligence, wisdom, insight, and personality so that you have your enlightened person whole again. So what is that skull that you were holding at the beginning?
What does it matter if an enlightened person is comprised of organic matter or not. Not comprised – represented by organic matter. Organic matter does what organic matter does – it metabolizes. It is created, it develops, it matures, it ages, and it dies.
The consciousness of an ordinary being is related to that biology, that physiology, regulated by it, maybe limited by it, controlled by it, and often people suffer because of their representative organic matter, but enlightenment is liberation from attachment to that biology and suffering because of it.
Organic matter isn't special. Even galaxy clusters, galaxies, star clusters, and stars go through a process that is organic. Our sun is metabolizing in an analogous way that our biological lives are. Our planet is also metabolizing in its own way with its numerous systems and transformation. The mountains are walking in meditation.
Enlightenment is recognition of the indestructible whole, the entirety of the cosmos that is one functioning organism or system, nothing is created, nothing is destroyed, there is no coming into being, there is no going out of being, there is just transformation. Even the shamans we call "physicists" describe that.
In the here and now of our actual lives, it is happening all around us. Enlightenment doesn't mean that all this happening around us is insignificant. It means that it is rich with the stuff of enlightenment. Enlightenment is found all around us in the here and the now.
The enlightenment of the Buddhadharma is not dependent on human existence (lots of humans have a problem with this concept. Bully). If humans didn't exist, the Buddhadharma still continues. It existed before humans evolved sentience, it will exist after humans are no longer here. The universe had no problem envisioning itself without humans for 99.999% of its existence. The earth will have no problem imagining itself when we are gone; basically the same as before we appeared. What is dependent upon human existence is its relevance, so we might as well take advantage of it while we're here and strive to live more enlightened lives.