I didn’t think it necessary to explain, but since you insist on trying wrest incorrect meaning from what I wrote I will spell it out for you.
The Jews did not know God as One God with Three Persons, as in the Trinity which we Christians have come to know Him.
The Jews did not and do not believe in the Trinity. To them, and according to what was revealed in the OT there is God, the Father; no God the Son and no God, the Holy Spirit.
It is the same God, but He revealed to us through Jesus that He is Father, Son and Holy Spirit.
So, God is the same, He is eternal and never changing, but the God we know through Jesus is not the God that the Jews knew.
Um, the Jews most certainly know about the Son and the Holy Spirit and they certainly did have the Scripture that told about them both.
The Holy Spirit is mentioned by name in the OT and all the prophecies about the Son revealed Him as well.
Psalm 51:11 Cast me not away from your presence, and take not your Holy Spirit from me.
Psalm 2:7-12 I will tell of the decree: The Lord said to me, “You are my Son; today I have begotten you. Ask of me, and I will make the nations your heritage, and the ends of the earth your possession. You shall break them with a rod of iron and dash them in pieces like a potter's vessel.”
Now therefore, O kings, be wise; be warned, O rulers of the earth. Serve the Lord with fear, and rejoice with trembling. Kiss the Son, lest he be angry, and you perish in the way, for his wrath is quickly kindled. Blessed are all who take refuge in him.
Isaiah 7:13-14 And he said, “Hear then, O house of David! Is it too little for you to weary men, that you weary my God also? Therefore the Lord himself will give you a sign. Behold, the virgin shall conceive and bear a son, and shall call his name Immanuel.
Isaiah 9:6 For to us a child is born, to us a son is given; and the government shall be upon his shoulder, and his name shall be called Wonderful Counselor, Mighty God, Everlasting Father, Prince of Peace.
# 841 The Church’s relationship with the Muslims. “The plan of salvation also includes those who acknowledge the Creator, in the first place amongst whom are the Muslims; these profess to hold the faith of Abraham, and together with us they adore the one, merciful God, mankind’s judge on the last day.”[330]