he is Jewish
The Jews. (Though strictly speaking, Jews do not believe that God is Jewish or that God has any religion.)
Jewish people only believe in one god.
Jews believe in One God, who created the universe. He is omnipotent. The words "What Jewish god" (in the question) are inapplicable, since we don't believe in "gods."
Abraham
He was born Jewish and raised Jewish. He believed in God, but he wasn't necessarily Jewish.
This isn't a question and therefore has no answer. I don't know if what you want for an answer is God, Judaism, the Holocaust, or any other significant event or figure in any way related to jewish history.
No. We believe that everyone will serve God. Everyone eventually becoming Jewish is never claimed.
Jewish believe in one God
Yes, we believe in a book. It's called the Torah and was given to us by God (Exodus 24:12).
Jewish belief is that God always exists. God is above time.
They don't, the Jews only believe in one God.