We sometimes paraphrase meaningful propositions in ways that are not strictly meaningful.
Take the proposition all Carbon 14 atoms will eventually decay. Literally, this proposition can never be tested. However, physicists would accept this as meaningful because they can translate it into a meaningful proposition, namely, the mean lifetime of Carbon 14 is 5,500 years. Technically, a Carbon 14 atom need never decay (though it would be extraordinarily improbable).
When you provide me with a philosophical proposition, I can try to squeeze it into a meaningful context, or paraphrase it so it does. I can almost always do this, as I demonstrated.
However, some propositions are designed to be resistant to this sort of reformulation. Suppose you give me just such a proposition:
A necessary, uncaused being exists.
If you accept my claim that a proposition must be part of a logical model and a choice of symbols to be meaningful, then we have to identify what that context is.
Here, you use the term "exists". You might mean this in a way that is different from when we say that "this cup of tea exists." We'll rewrite your verb as $exists until we know what it means.
For everyday, physical objects, existence is predicated on a specific definition of what empirical attributes the objects have. They are said to exist not when we can imagine them, but when we observe them.
For example, if you say that "a cup of tea exists on the table", and I look at the table and find that there is only a bowl of sugar on the table, then I have falsified your claim. Without these tests the verb to exist would be useless because elephants could exist on the table just as well.
So in your proposition, what are the specific, observable qualities of this being that would afford its existence if we observed them?
If you don't have any such qualities, then the verb you are using is just $exists not normal exists.
In the latter case, what does $exists mean? Perhaps, it is the fictional interpretation of exists, e.g., Chewbacca's third heart exists if we could only do an MRI on him in the Star Wars Universe. I doubt this because you have not shown what experiment, real or fictional would validate your claim.
Your claim is that this being (whatever a being is in this context) has a property of $existence which is as yet undefined. This is what I mean when I say it is meaningless.
The fact that confused people, some philosophers among them, feel they "understand" your proposition is not adequate to make your case. People think they understand a lot of things that they don't. In this specific case, people have an intuitive sense of what existence is. In their brains there is a cluster of neurons that fires when the concept of existence is triggered. This region forms as we grow up, using the verb to exist in the coffee cup sense. However, once we have a word for this existence property, it is tempting to trigger this region of the brain out of context. It is tempting to say that existence is just an attribute of a thing that makes it real.
This is confusing to us because we intuitively think things can exist independently of their properties. Next, we start saying X exists where X is something unobservable. It sounds grammatically correct, and it seems intuitively possible, but it is actually nonsense. It is a psychological illusion.
Now, your proposition may still form part of a logical structure, but unless you can define $exists in some rigorous way, you really aren't saying anything about the world.
Suppose you provide me some other interlocking propositions. Maybe "If a being A $exists, then there is a being B that does not $exist". (I have no idea what this means, but it would seem to logically relate to your proposition.) Even in that case, none of your interlocking propositions have any empirical consequences except for their own computational self-consistency. What makes such a proposition about the world? Nothing, I would say.