I never said that They are 3 manifestations of One Being.
I said that They are 3 different Entities / Parts (or Persons) of One Definitive BEING.
You yourself consist of a head, a body, and a spirit...do you not? 3 different / distinct parts.
Yet those 3 parts are what make up you (singular), as a whole.
I could take a photo of just your head, and show it to your family members.
And if i asked them who is that picture of? They would likely reply "its SovereignGrace!".
And likewise if i took a photo of just your body and asked them who this was, they would likely say "its SovereignGrace as well!" ...coz they would most likely recognize your clothing and know your build, being family members n all.
So whether its your head, or your body....its still identified as you.
And so in the same way, God the Father is the Head, and God the Son is the Body.
Yet They are 2 different portions of the same Being.
Whether i call the Father GOD, or Jesus God....I am referring to the same Being in the bigger picture. But, just a different portion of that Being...depending on who i am referring to.