The sixth chapter of Genesis begins with a puzzling episode in which “sons of gods” (to render the phrase literally) mate with human women to produce a race of giants. At this point, God announces that the human lifespan will henceforth be capped at 120 years. Benjamin Sommer notes that legends of deities begetting quasi-divine offspring with mortal consorts were common in ancient Near Eastern and Greek myth, but seem out of place in the monotheistic Torah. Yet the tale of the giants may not be so anomalous after all:
In Greek and Mesopotamian literature, gods become mortals, and humans divine—all of which points to a fundamental similarity between humanity and divinity in these ancient texts. The very core of polytheism is not simply that there are many gods but that gods and humans are made of the same stuff. Conversely, the Bible does not claim that God is the only heavenly being; after all, there are angels.
The core of biblical monotheism, as the German-Jewish philosopher Hermann Cohen and the great Israeli biblical scholar Yehezkel Kaufmann showed, is something else: that God is unique. Even as Scripture demands that human beings attempt to imitate God, it also stresses they need to realize they will never fully succeed in doing so. It is for this reason that the book of Genesis includes this brief and surprising tale. . . .
It was hard for ancient people to admit it, and it’s even harder for moderns, but the Torah teaches that humanity has limits, and it’s not our role to play God.
Read more on theTorah.com: http://thetorah.com/why-are-there-demigods-in-a-monotheistic-torah/