Looking up the meaning of pantheism after reading this post, I couldn't help but think it's another new age god replacement sort of religion. I read lots of definitions. I didn't read anything about proof or evidence. I don't see it as anything to do with atheism.

you ask, "The big question is... what is everything anyways?" In English, I would say you could sum it up in one word: Force. Force(s) is/are everywhere.
Force
noun

1. strength or energy as an attribute of physical action or movement.
   "he was thrown backward by the force of the explosion"
   Similar: strength power energy might ...

verb

1. make a way through or into by physical strength; break open by force.
   "they broke into Fred's house and forced every cupboard door with axe or crowbar"
   Similar: break open force open burst open ...

kinetic energy
PHYSICS
noun: kinetic energy; plural noun: kinetic energies
energy which a body possesses by virtue of being in motion.

Force = mass x acceleration

Atoms have a force capable of occupying a volume of space of given circumstances.

Knowledge and information transfer are done in connection with forces. kinetic energy of air molecules bouncing against the ear drum with a pattern transferring information.

For understanding biblical text for it's original intended meaning I do not like using the word spirit. I think spirit has too much of a connotation to ghost and sometimes in English biblical text the word ghost is used.

In Hebrew the word ruach is a force like breath, wind or a storm. It is often connected with communication or information being given. In parts of new testiment when Greek was used Pneuma they were using the using the Greek work pneuma for the Hebrew work ruach. In English these are most commonly translated as spirit.

His spirit can be said to be the emanation of His life-force - i.e. breath

Definition of spirit/ruach: “The basic meaning of ruach is both ‘wind’ or ‘breath,’ but neither is understood as essence; rather it is the power encountered in the breath and the wind, whose whence and whither remains mysterious… 2. ruach as a designation for the wind is necessarily something found in motion with the power to set other things in motion… [en.wikibooks.org]

I prefer it’s other meaning, that everyone is atheist to some religions. What a common denominator

It has its uses.

For example, in grad school, an outspoken evangelical kept trying to convert me for about a month. Finally, one day in the cafeteria I sat down and bowed my head before supper. He was shocked that I was saying grace. I told him, no, I was thanking the chicken. It gave its life for me.

He never spoke to me again.

Actually, pantheism posits many gods & predates most of the religions around today. For example, thank a tree before you cut it for your use (not just cut it) or thank a deer/buffalo/ wildebeest for giving its' life for you. Everything (potentially) has a spirit inside.
So Not "sexed up atheism" but a lovely reverence for the living things around us

In a way, as an 'agnostic Neo-Deist, I AM a pantheist, which is a far cry from being an atheist, "sexed up" or not.
Are you serious with such an ignorant remark?
Pantheism, or neo-deism, allows for 'natural law,' an afterlife, and many other things atheists scoff at.
'Everything,' "anyways," is the 'collective unconsciousness,' or universal consciousness, and postulates 'everything' is connected and interrelated. It's not a deity, a divine entity, but rather all of the material world, both matter and energy (which are the same thing in different form).

The Buddhist says that everything is mind. The Buddhist also says that everything is Buddha. We don't want to get to bogged down with semantics. But I guess there is no SUPREME being but THE being. So you might call it atheistic. But then life after death, (reincarnation,) as well as spirits are involved. There is also a great deal of meaning involved. I guess it developed independently from Abrahamic religions, so it is hard for an Abrahamic to identify it as religion.

The opposite of nothing.

Is not Pantheism merely by definition replacing the single God Being with multiple God Beings, i.e. the Roman Pantheon, the Greek Pantheon, the Pantheons of ancient cultures or even the Pantheon of Hinduism?
Did not Christianity, for one, strive from its very beginning to destroy and drive out Pantheism and the beliefs of there being a vast Pantheon of Divine, Supreme Beings?
Ergo, Pantheism is not and cannot be "sexed up Atheism" since Atheism by its very definition is a DISBELIEF/Rejection of the notion/ideology that ANY and ALL Gods/Supreme Divine Entities have never existed.

If people want to call the universe, or all of reality, "God" - fine, thats just symantecs. But it being self-aware? Thats an entirely different ballgame, and improbable enough its a waste to put lots of resources into it.

Pantheism is not sexed-up atheism.

To define God as "everything" is an abuse of the English language.

Einstein was fully entitled to his own world view.

I define everything as the observable universe.

What is everything? I cast my vote for the absence of nothing.

Pantheism, a belief that god, whatever it / she / he represents, permeates everything, is not scientifically demonstrable, nor is it 'sexed up atheism.' One may as well refer to it as 'the Force.' And what is the 'essence' or 'particle' that we can observe and measure in everything that is god? If the pantheistic version of god is not beyond nature, but in nature, why call it god? Why not call it nature itself, or the universe?

Pantheism is the view that the world is either identical to God, or an expression of God's nature. It comes from 'pan' meaning all, and 'theism,' which means belief in God. So according to pantheism, “God is everything and everything is God. IMHO, we use the word "god" because it is a convenient word to use for something that really cannot be defined. And, no I do not believe in the usual definition of a "god". I don't believe in any "god" but just if ya wanna call all of us "god" ok with that because we are with all the other stuff in the universe, the universe.