Rabbi Berel Wein
In a world of paganism and self-definition of "truth", Abraham taught G-d consciousness, absolute truth, and the importance of morality. He and his wife Sarah die and are buried in the cave of Machpela- which Abraham purchased at great expense in order that it should be the burial place of our patriarchs and matriarchs (and it still is today).
Before Abraham dies however, he sends a messenger to find a wife for his son Issac, since finding the right mate is probably the most important decision anyone can make in life. Rebecca, who comes from a pagan background (King Solomon describes her as being a rose among the thorns), comes to Isaac as a holy person. They become married and build a home together in the land of Israel where they continue the tradition of teaching Monotheism, goodness, and morality. Isaac and Rebecca are the only ones of the patriarchs and matriarchs who never leave the land of Israel.
After Abraham's death, the leadership then passes to Isaac and Rebecca, because Abraham's other son Ishmael doesn't want the to take on the responsibilities and feeling of being alone in the world. Ishmael goes so far as reverting to paganism and crafts of violence, robbery, and subterfuge.
Taught by Rabbi Berel Wein - http://jewishhistory.org