Exist-no change with time

If someone or something change with time we can't say that being or thing exist.

Difference between exist and present

Someone is present means 

He is present at a particular time 

His presence is related to time. He may change with time. 

Someone exist means 

He is unchanging with time. 

Exist and eternal

Eternal is without beginning or end. 

Someone always present or exist should be eternal. 

But someone who exist

 is not only eternal he should be unchanging ,same yesterday today and tomorrow. 

Exist and definition of God

Root meaning of exist is stand forth. If something or someone doesn't  remain always,according to core word meaning we can't say that thing or being  exist. 

We can say he or it is present for a particular time. 

Humans do not exist always. 

Material objects don't exist always. 

Exist means always present. 

It is He Who always present or exist we call God. 

Then the question God is a concept or object. 

Concepts doesn't present always so don't really exist 

Material objects doesn't present always so don't really exist. 

According to definition of God,He who exist is God. We can't say God is a concept or material object. Because concept and material objects don't present always or don't really exist 

Who exist? What exist

There is a difference between these two questions ,what exist ? and who exists?

What exist?

It is about a thing. It exists. It is about matter only. Matter present for a long time. But it may also undergo disintegration. When we don't know. 

Who exists?

It is about a person. We know a person is made up of matter. But person is not matter alone. 

I will explain with an example. 

My grandpa expired 25 years back. 

25 years before he existed as a person. 

Now his bony elements exist in the graveyard. Elements of his bone and body existed before him. Those elements will exist after him. But he existed only for a short period .

 So the better term would be he was present for a short period.

His body elements are present for a long period. Those elements also may not exist always. 

If we say he was a particular configuration and that configuration cease to exist then there is possibility that we can again reconfigure that person. Then we have to say my grandpa existed, now not existing,in the future he may exist again. But better term will be he was present,now not present and in the future he may resurrect or reconfigured. 

Who exist 

Person 

But human person exist for a short period. So we can say humans present for a short period. 

So if we say a person really exist the meaning is that person always present. 

Difference between exist and present.

As a person I can't say I exist always. 

So my existence as a person is a limited existence. 

So I can say I am present because I exist now only. Not in the remote past not in the remote future.

 

As a person who always exist?

who exist in the past, present and future. 

The word exist can fit only to such a person. 

So I can say I am present. 

But who is that "I am" always present or 

Who is the person who really exist?