Do you not understand the nature of the Trinity? Father, Son, and Holy Spirit? All three are one.
That is a Christian belief for the purpose of Christianity and of Christians. Developed in time as Christianity grew and took the place of Paganism.
As I said before, Judaism has only one G-D, one only. For 1800 years before Christianity and after it, it continues to be that way.
No human being is born and takes shape as the G-D of Abraham and take his place.
First Commandment: Thou Shall Not Have Any Other Gods but me.
It is that way because of all the other Pagan gods which existed, including the ones Abraham abandoned to follow the G-D he chose to follow, which he did all the way to Canaan.
Your Trinity is a pagan idea. Many who followed Christianity could not abandon their pagan ideas, and this is one of them.
A Demigod is born to a god and a female human being. That is Hercules and many other mythical Demigods of the time and of the area. You may research all of that.
It was never Judaism, for the simple fact that Abraham rejected paganism and all its many gods and idolatry and chose to follow one G-D, and one G-D only.
Which means that Jesus, a Jew who was also a religious Rabbi, followed in Abrham's footsteps of following one G-D, the G-D of Abraham.
I understand that your religious education makes it difficult to understand that. It is all in the Hebrew Scriptures.
All that is written in the NT is borrowed from prophecies in the Hebrew Scriptures because some of Paul of Tarsus, who were educated felt that those phrophecies were connected to what they had heard or read about Jesus from Paul himself and his letters.
These were people who did not live at the time of Jesus, not even Paul of Tarsus, and never met him. They believed because of the need to believe and need to deal with the Romans who had conquered all of their world, from England to Judea, etc.
This is the best I can do to explain the difference between Judaism and Christianity.
Had Paul of Tarsus not accused Jews of this and that Christianity would never have gone after the Jews at any time. It would have been simply another believe, cult, religion. The accusations of killing a Demigod who was supposed to save the world, all humans, bring peace to the world, made all the difference.