Thinking about Spirit

As I was on my computer, early this AM, I also said a morning prayer.  Not the first of the morning as I try to pray continuously.(impossible for me at all times, but at every time I think of it).
Anyway, I began to wonder when Mankind first began to worship the God within, The Holy Spirit, or just Spirit.
I thought of ancient man worshiping trees and rocks and animal spirits.  I thought of Greek and Roman Gods like Zeus, etc. I thought of the Jewish un-named God, Yahweh, I thought of the Muslim God Allah. I thought of Hindu Gods like Krishna; and  Buddha.
Most, if not all of these Gods were and are worshipped externally.  They are worshiped as mountains, statues, at Holy places like Mecca and Jerusalem, and countless other places around the world which are deemed to represent the dwelling place of God.  Temples, synagogues, churches.  Countless fields( Stonehenge), mountains, waters( like the Ganges), many, many Spirit filled places.
God has appeared to men and women, and even children, in dreams, visions and prophesies, altered states and told them many things, instructions, the future, etc. 
I wondered when however, the first of humankind began to worship the God within each one of us? How and when did the external become internal as well, or was it always so? 
This is not a learned discussion.  I have done no research, not do I intend to. Far better and more educated minds than mine have most likely thought about, written about and discussed this question.My thinking tells me that we acknowledged this Spirit within as God when Jesus said

And I will send to you my Spirit of Truth.

"But when he, the Spirit of truth, comes, he will guide you into all the truth. He will not speak on his own; he will speak only what he hears, and he will tell you what is yet to come."

John 16:12-14

I welcome your comments and feedback.  PooBah

I had a prophetic? dream

I had a dream last night and saw a diorama of Revelations 12:12.  I had gone home to Potsdam and my parents were still alive.  I was helping my mom make her bed and the comforter was much too wide and really misshapen.  I asked her why she had that one and she said it was the only one she could get on sale. Our two bedrooms were connected with a door between and the stairs came up into my bedroom. (This was the same as in my youth.)  My parents had the side bedroom and I had the one at the top of the stairs.
  I went to the door between our rooms and noticed large diorama set into the area between the window and my closet. It was a little stage set all done in dark shadows and grey white ash.  There was a burned building structure covered with grey ash. The structures of the neighboring trees, their trunks and branches were all covered in grey ash.  The landscape was also covered in ash but the underlying structures could be made out of  contrast dark shadow to the white ash.  There was no life in the diorama anywhere.  I said what is this and was answered by a voice saying Revelations 12:12. 
Now, I do not like the book of Revelations and have never read the book completely, only skimmed it..  I have always felt it was an allegorical struggle between the Romans and the Jews and forecast the end of Jerusalem.
I woke up with the words " Revelations 12:12" ringing in my ears.  Since the words are still there and I looked up the verse, I felt I had better write about it.