Concepts such as infinity and oneness are problematic in terms of our capability to describe them accurately. While it can be argued that perception and language are always inaccurate representations of reality, we judge the fitness, accuracy and consistency of representations based on comparison and our concept of knowledge.
For example, in mathematics we have a concept of unity that we call "one". The mathematical "one" can be identified as single object and is considered equal to or identical to the collection of components that together form the object. We consider this model to be an accurate representations since it has consistency logically and physically. When we compare principles to the physical objects or the theoretical ones there is a high degree of consistency for the representation.
The concept of oneness in mathematics where a theoretical "one" (object or quantity) is equal to the sum of its parts is based on an object model. In this model the unity/object and the parts are essentially defined in terms of each other. This is the situation where 6 describes the unity in one way and a half-dozen describes the same entity it in another.
The object or objects (depending on how you reference it/them) do not change regardless of which reference is used. What changes between the two references is where you draw the line or lines in the your multiplicity model. In the object world view the identification as a single entity (for example a man) or 6 parts (such as arms, legs, torso and head) is a matter of grouping.
Mathematics and logic only apply in a reality that contains multiple objects. A is not equal to A in the absence of multiplicity nor does 1 plus 1 equal 2. The concept of number, the rules of logic and the language of things are not applicable for a non-object state.
Non-object does not mean non-being. In this instance, non-object is meant to identify the condition as lacking division or multiplicity.
I would argue that "being" is evident and beyond meaningful debate. I would also argue that we have and use a model of multiplicity that is consistent with our experiences and has practical application. However, our experience, logic and mathematics drive us toward the conclusion that "oneness" and therefore mystery are a necessity of the human condition.
The short version of my argument is as follows:
(1) there is being
(2) there is only being (no non-being)
(3) if there is only being there is oneness
(4) if there is oneness there is mystery because human knowledge requires multiplicity
Human knowledge requires multiplicity because all definitions of knowledge include a perceiver and something that they understand or are aware of. Knowledge cannot occur in the absence multiplicity and the perception relationship.
This is In addition to the previous claim that logic does not apply in the absence of pluralism. The "one" that we discuss in mathematics is relational unity in a universe of multiplicities of relational unities. It is not "oneness" in the sense of "being" without "division".
Indivisible being/existence cannot be described adequately by object language. This is similar to the issue of reflection mentioned in the cave analogy of Plato’s republic but the gaps in the accuracy of the representations are more severe.
For this example, the analogies from the creation story in the King James Version of the Bible might be more appropriate. The following passages have been taken from the book of Genesis:
"And out of the ground made the LORD God to grow every tree that is pleasant to the sight, and good for food; the tree of life also in the midst of the garden, and the tree of knowledge of good and evil." Genesis 2:9
"And the LORD God said, Behold, the man is become as one of us, to know good and evil: and now, lest he put forth his hand, and take also of the tree of life, and eat, and live for ever:" Genesis 3:22
The first passage refers to the achievement of referential knowledge of a material nature. This is the understanding of objects, division
and opposition. These are limited entities where the rules of number, math and logic apply.
The second passage introduces the concepts of the eternal, the limitless and the indivisible (oneness).
The infinite is beyond knowledge.