I find these kinds of reasoning amusing.
They never start with, "we have this memory of being connected to something greater" and so we seek out that connection in our lives.
But, here in the west, we don't even believe in Qi, although it has been scientifically measured. We don't believe in meditations, we think it is for insane people on mountain tops, but its effects have been scientifically measured.
So, we go into this question with our hands tied behind our backs, and come up with all kinds of plausible sounding ideas without understanding the basis. Its like trying to explain thunder without ever having seen lightning.
What if those "imaginary" friends are actually real, just not visible? Especially by older people who have trained themselves not to see.
And, what if there was a God who you could, at first, feel a connection to, and then as you strengthened the connection actually communicate with and get to know?
But, "scientific" people tell people that's crazy talk.... and believe instead in the Big Bag theory... which should have been thrown out, because our universe shows to much structure to be started with just an explosion.