How can we take an "if" as a premise?
Hypotheticals form unsound arguments.
There's a reason quantum physicists don't bother with hypotheticals. They're interested in what's observed. "If a tree falls in the forest and nobody is around to hear it, did it make a sound?" Answer: The question is pointless and fails to beget an answer.
You propose only nihilism because arguments at this level must take faith in prior axioms.
However the funny thing is that I am arguing for the lowest skeptical viewpoint possible: the only thing that can be proven to your perception is your own perception. Nothing else can be proved to be observable outside of the realm of self.
I don't propose nihilism at all. Truth cannot be known through thought or through words. You cannot abstract it if you want to truly know it. And, faith is critically important to happiness and is arguably one of the root causes of our ability to survive. Faith basically boils down to intention.
"What one can know, he cannot prove. What one can prove, he cannot know."
Truth is varying human concepts only catering to various human desires. It cannot be known universally. Objective reality, which one can consider truth, just is. It does not have any ties to the human perception, assuming anything exists outside your individual perception.
Let me make that clear:
It just is.Ones own truth can be known to oneself through whatever medium they please, whether it be through words or cognitive means.
Intention does not have meaning to all individuals.
Anyways, I can believe some things are more probable than others but I cannot have complete faith in anything. I cannot even choose to do so. Some systems always inevitably fail even when such failure was not expected.
Immortality has yet to be proven in some observable systems. Even immortality as a concept, may find itself non-existent.
Now if non-existence and existence were to cease as concepts... What if the rules saying in order for they to be existence there must be nonexistence ceased?
Then what exists outside of existence? Can there be a plane of perception outside of this?
Goddamn, I am going to fucking bed.
In the end, currently, existence can only be defined within your individual perception. All else is pedantry.