Abraham is referred to as "our Father" in both the bible and the Quran. For this reason, Judaism, Christianity and Islam are considered "Abrahamic religions".
According to the book of Genesis, Abraham is the founding patriarch of the Israelites and other kindred peoples.
Jews, Christians, and Muslims consider Abraham to be the father of the people of Israel. For Jews and Christians this is through his son Isaac, by his wife Sarah.
Muslims also believe that Abraham is a prophet of Islam and the ancestor of Muhammad. For Muslims this is through his son Ishmael, by his wife Hagar, Sarah's handmaiden.