I believe they all have the same four books of the old testament in common - Genesis, Exodus, Leviticus and Numbers. They all claim to worship the same God, although I have my doubts about this part. Also, the 12 Hebrew tribes purported to be "God's chosen people" claim they are descendants of Abraham's first born while Muslims also claim to be "God's chosen people" from Abraham's first born. This is the story of Isaac and Ishmael. The Jews claim that Isaac was the firstborn of Abraham will the Muslims claim that Ishmael was the firstborn of Abraham. Muslims maintain that Ishmael was the firstborn of Abraham because Abraham slept with his Egyptian handmaid servant named Hagar and she gave birth to Ishmael first. But later, Abraham's wife Sarah actually gave birth to Isaac which was technically their first biological son together. In the KJV Holy Bible, God is purported to tell Abraham later on that although Ismael's children will become a great nation, the promise is to be passed through Isaac's line of descendants.