Christians adopted the Hebrew scriptures as their own Old Testament, and therefore accepted Abraham as the founder of Judaism. Being unable to claim genetic descent from Abraham in the way that Jews could, they claim spiritual descent from him.
By the time Muhammad began to preach the Islamic religion, Judaism and Christianity had both won significant converts in the Arabian peninsula, bring with them the legend that Abraham was the forefather of the Arabic people. This became part of Islamic tradition. For Muslims, Abraham thereffore also has a revered position in tradition.
Jewish and Christian Answer
Tradition holds that Abraham founded Judaism around 2000 BCE when he renounced idol worship, acknowledged the existence of one God above all others, circumcized himself, and offered animal sacrifices to God.
Christianity was born 2000 years later, and Islam was born 2600 years later.
Muslim Answer
Abraham was born among people who were worshiping idols. He was guided by God to worship the one and only one God, the Creator. Accordingly, He was submitting fully to God the one and only one God with no partner and no associate. This is the very basic rule of Islam (that is an Arabic word meaning submission to God the one and only one God). So, Abraham was Muslim; in Islam universal sense, and all God prophets before him and after him (peace be upon them all) were Muslims and they called their people to Islam. The prophets; Moses, Jesus, and Muhammad; of the three religions Judaism, Christianity, and Islam came after prophet Abraham.
At Sarah's urging, Abraham took her handmaiden, Hagar, and had a son by her, called Ishmael.
Later, Abraham was promised by God a son with Sarah. Sarah became pregnant and gave birth to Isaac.
Because Ishmael was older than Isaac, Sarah had Hagar sent away, with Ishmael, as God commanded, to ensure that Abraham's inheritance went to Isaac. God provided for Hagar and Ishmael promising to make their descendants a great nation, too.
From Ishmael came forth Arab nations and Islam; from Isaac came the Jewish people. Jesus was of Jewish birth, and thus we, as Christians recognise the importance of the Jewish patriarchs of the Old Testament.
Hazrat Abraham had two sons. Hazrat Ismaiel (AS) from his wife Hazrat Hajra (AS). The off-spring of Hazrat Ismaiel (AS) settled in Arabia. The Last Prophet of Islam Hazrat Muhammad (SAW) was from his off-spring. So Hazrat Abraham (AS) is one of the most respected Prophets of Allah Almighty for the Muslims.
The second son of Hazrat Abraham (AS) was Hazrat Ishaq (AS) from his wife Hazrat Sara (AS). Many of the Prophets were from his lineage. Hazrat Jackob (AS), Hazrat Joseph (AS), Hazrat David, Hazrat Soloman, Hazrat Moses (May peace and blessings be on all of them). The Jews are from that lineage.
Hazrat Jesus Christ (May peace be upon him) was also from the lineage of Hazrat Moses (AS). Thus the Christians also respect Hazrat Abraham (AS).
Abraham founded Judaism; and Christianity and Islam are Judaism's daughter-religions. And physically speaking, the Israelites and Arabs are descendants of Abraham. See also the Related Links.
Judaism, Christianity, and Islam religions.
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.
Abraham founded Judaism. Christianity and Islam are daughter-religions of Judaism.See also the Related Links.Link: How Abraham founded JudaismLink: Was Islam's inception influenced by Judaism
Abraham.
Both Islam and Christianity originated out of Judaism.
Judaism, Christianity, and Islam.
For Judaism: http://judaism.answers.com/jewish-history/a-biography-of-abraham
Christianity, Islam, Judaism & even Baha'i all have a mutual ancestor: Abraham.
Christianity and Islam both trace their roots to Judaism.
The connection between Islam, Christianity and Judaism is that the three religions trace their history to the covenant between God and Abraham.
Christianity, Judaism and Islam
Abraham