Q. Why does it stop at three? Why doesn't God the Son for example have perfect knowledge of himself and beget God the Grandson?
A. Immensely difficult question. The best answer I make do with? Think of the Son as the "result" of the intellect and the Spirit as a "result" of the will. There can only be one Son and one Spirit because God's nature has only one intellect and only one will.
God's act of knowing Himself and of loving Himself is perfect. Grandsons and other spirits would imply His first act of knowing or of loving were not perfect and thus simple/unitary/one.
Q. And why do we call God "he" when being a spirit with no body He has no sex? Isn't that a bit chauvinistic?
A. Well... At the end of the day, it's because Jesus himself used the masculine articles and only the masculine articles whenever He referred to the Father or the Holy Spirit.
Whether He did that because of the cultural patriarchal environment He lived in is another debate altogether. Fact is He always referred to the Father as "Father" or "He"; and He always referred to the Spirit as "He". Our attempts at rebranding to "God the mother" or "God the progenitor" or "God the single parent" however well-intentioned they are do not follow Christ's supreme example.
Q. And from the way you explained it, isn't it clear that God the Father is like more important or primal or powerful compared to the other two? As in, in the very least He must have come BEFORE the other two.
A. Yes it would seem so. However the best way I have heard of explaining this came from a little boy who would attend Sunday School despite his atheist father's silent disapproval.
One Sunday, the boy came home from Sunday School and the father thought he'd engage him in light conversation.
"So what did you guys learn at Sunday School today?"
"About God."
"What about Him?"
"That God is three and at the same time one. He is three EQUAL Persons but one infinite God."
"But how is that possible when God the Father came BEFORE God the Son? I mean: I am your father you are my son; I came before you."
"Yes dad. But you did not become a father until I became a son."
Happy Corpus Christi feastday!
29th May 2016