knife. >> as the story goes, abraham literally lifts the knife before god says to him, abraham, abraham, you don't have to do this. >> so, the son was spared. and a lamb appeared to take his place. >> one of the abiding lessons we're meant to learn from genesis is obedience to god. that if you are obedient, that in the end, you are rewarded. >> muslims believe ishmael, not isaac, was the son abraham was called upon to sacrifice. but the essence of the story is the same across the three religions. is it heartbreaking to think this patriarch, this person who we believe is the father of our religions, was this close to committing murder, killing his son? >> i don't know if it's heart breaking or not, but i know it's eye opening and it's important,