It's essence is acorn. You are trying to make 'essence' mean something it doesn't.
'Essence' does not mean 'what this will some day turn into'.
Absolutely correct. The acorn will become an oak tree, but the oak tree is not different in substance from the acorn. Everything that the oak tree IS as an Oak Tree is in the acorn.
An acorn is just an oak tree that has not yet begun the process of development. An acorn is what an oak tree looks like when it is a seed.
They're different. One is a tree; one is a seed.
Of course they are different; but not in essence. An oak tree is just the acorn in its developed state. An acorn is an oak tree in its undeveloped state; seed form. An acorn is what an oak tree looks like at that stage. An oak tree is what an acorn looks like at that state.
Acorn, sapling, young tree, fully grown tree, those are just terms that refer to the tree in different stages of development.
It's an acorn. I'm not sure how many times this needs to be said to you.
And what IS an acorn? A seed. And what seed is it? A pig? A flower? A maple? No. OAK.
All you are doing is trying to come up with some word according to which an acorn and an oak tree are the same thing.
They are not the same thing--if by that you refer to appearances and stages of development. Just like a toddler and an adult are different in appearance, but the same in essence. Just like a foetus and an infant are the same in essence but different in appearance and development.
It won't work. They're not the same by essence, nature, kind or anything else.
If and acorn is different in essence from an oak tree, when does the acorn become oak? What is it before it becomes oak?
They are different things. An acorn may, if all goes well, grow into an oak tree. It is not an oak tree.
Then what is it? A pig?
When does--whatever it is become something different--that is--when does it become oak?