Unknown by definition is the
not known; not within the range of one’sknowledge, experience, or understanding; strange; unfamiliar.
Source: Dictionary.com
Exist is to have actual being or be.
Source: Dictionary.com
Therefore, Does not exist is not being or not to be.
Just because someone does not see something, it does not mean it does not exist. After all, love is an unseen attribute but it exist. The force of gravity exist but it cannot seen by the eye. The ultraviolet light cannot been seen by the eye. Only when we use a machine, the ultraviolet light is revealed.
In an imperfect world, there is imperfect eyesight. Therefore, unseen things cannot be discarded because it is not seen.
Most atheist confuse the words does not exist with unknown. Unknown has the characteristic of being or existing. Ultraviolet light exist but cannot be seen. The existence of multiple many more colors beyond ultraviolet exist but it does not mean they do not exist only unknown.
In the same way, God existence is demanded by the attributes and logical arguments that point to being.
Exodus 3:14
God said to Moses, “I am who I am. This is what you are to say to the Israelites: ‘I am has sent me to you.’”
I am or Be. The concept of existing but not seen. Unknown does not mean does not exist. Unknown means that it has not been discovered but is there. It is already created but untouched by our broken human limitations of seen a world beyond our human eye and brain. Unknown is waiting to be discover and revealed to each of us.
The maximum and ultimate unknown is the creator of everything. It does not mean it does not exist. The Creator of everything is also known as God or I AM .
Apologetics 