Abraham was descended from Sham, the son of Noah who were allegedly members of the Horite Tribe. Abraham's father was named Terah, and his mother was named Amathlaah. Terah and Amathiaah were allegedly half-brother, half-sister.
Abraham Lincoln is not a religion. Prophet Abraham lived long before Abe lincoln and the prophet Abraham's family started Judaism, which is the base for Christianity.
Christianity and Islam both originated from Judaism.
Judaism, Christianity, Islam, & Baha'i.
Let us suppose that Abram was a real historical person who founded Judaism. Then we could regard him as the spiritual ancestor of those who now follow Judaism or its daughter religions, Christianity and Islam.
Islam is an Abrahamic religion, and thus has its roots in Judaism and is connected to Christianity, as they all worship the same god. Islam originated with the prophet Muhammad, who Muslims believe to be a prophet of the god of Abraham.
Christianity and Islam are two major religions that evolved from the Hebrew religion. Christianity was founded by Jesus of Nazareth, who was a Jew and claimed to be the fulfilled Messiah promised in the Hebrew scriptures. Islam, founded by the Prophet Muhammad, recognizes many of the same prophets as Judaism and Christianity, including Abraham and Moses.
Abraham was the "father" of the three major religions because it was from his "seed" that the Founders of each religion descended: Abraham & Sarah begat Isaac from whose line came Moses & Jesus (Judaism & Christianity) Abraham & Hagar begat Ishmael from whose line came Muhammad (Islam)
They are descended from him.
The word Monotheism applies in contexts that refer to the worship of One God. According to tradition, Western Monotheism was founded by Abraham.
They all respect Abraham and Moses. They were originally the same religion. They believe in one God.
Abraham is looked upon as the "Father of the Prophets" by Judaism, Christianity and Islam. He is revered in all three.