Jewish answer:
The Hebrew Bible is important because it tells the history of the ancient Israelites, as well as giving us the teachings of such prophets as Moses, Isaiah and Jeremiah, the stories of kings like David and Saul, and the development of the ethics and beliefs of the Jewish religion. Our tradition is that the Hebrew Bible is from God (Exodus 24:12), given to us to provide knowledge, guidance, inspiration, awe and reverence, advice, law, comfort, history and more. It is the basis of Judaism.
The Hebrew Bible has also heavily influenced Western society.
Abraham is considered the father of Judaism, Christianity and Islam as the Old Testament's 5 books of Moses - The Pentateuch (books are: Genesis, Exodus, Leviticus, Numeri and Deuteronomy) are included in the Holy Book of Judaism that is Torah. Eventually he is considered as the father of Islam basically claims entire religions of Judaism and Christianity as "prophets" and predecessors of Islam.
Islam, Judaism and Christianity.
Judaism: Tanakh (Hebrew Bible) Christianity: Bible Islam: Holy Quran
Judaism, Christianity, and Islam have all claimed the Holy Land for themselves.
Judaism, Christianity, and Islam religions.
For Judaism and Christianity it is Jerusalem. For Islam it is Mecca.
-- Islam -- Judaism -- Christianity
Christianity and Judaism
Judaism and Christianity share all the prophets of the Old Testament while Islam recognizes about 20 with the major exception being Ishmael which only Islam considers a prophet. Judaism recognizes no New Testament prophets which ends with Jesus Christ while Islam recognizes about 3 or so which includes Jesus Christ.
Judaism and Christianity have the bulk of the old testament in common. However Islam draws some of its source material from biblical stories but re-interprets it, so it does not have anything in common in terms of the bible.
The question should be " What does Christianity have to do with Jews (or Judaism)?" Judaism is like a tree where Christianity is its branch and Islam is it leaves. Christianity is based on Judaism and Islam is based on Christianity. The major difference between the three is that Judaism doesn't have jesus in it unlike Christianity and Islam.
Judaism, Islam and Christianity all worship the same, SINGULAR God. The writings of the Jewish Torah and the Christian Old Testament are revered in Islam.