Pat M. answered 08/26/20
Skilled with experience in comparative and world religions
Jews rightly claim Abraham as the father of the Jewish nation because biologically the Jews were his offspring through his son Isaac by Sarah.
Muslims claim Abraham as the father of their faith by tracing their biological lineage to Ishmael, Abraham's son by his wife's slave Hagar. They also claim that Ishmael was the blessed one and not Isaac.
Christians claim Abraham as the father of our faith because Jesus is descended from Abraham through Isaac. The faith that Jesus taught was Abraham's faith.