How did it happen that some Second Temple sources define piety as abstaining from sex on Shabbat, but that the Rabbis defined Shabbat by the embrace of this very activity? Devising a binary between Second Temple Judaism and Greek Culture on the one hand and a binary between Rabbinic Judaism and the Christian Religion on the other may offer us some limited insight but not a complete, nuanced answer. The fact is that the demarcation lines are very blurred between Second Temple Jewry and Hellenism, and Rabbinic Jewry and Christianity. There is compelling evidence that Jews participated in Greek gymnasiums and attended Greek philosophical schools, and there is also evidence that Christians were practicing Jewish customs as late as the fourth century.
If we presume that the Second Temple Jewish tendency towards asceticism and the rabbinic tendency towards indulgence represent polemical responses to outside enemies, incompatible with their own lifestyles, we easily forget the internal conflicts within these Jewish communities that also helped these groups to formulate their identities. As unsatisfying as it is, the question of whether there is a direct sociocultural link between these attitudes may be lost for perpetuity.
Although we may not be able to know how this change occurred, we can nevertheless appreciate the ingenuity of the rabbis in nurturing the experiential and sensual aspects of Judaism. By encouraging marital intimacy on the Sabbath, and by composing blessings for even the basest of bodily functions, Rabbinic traditions invite us to merge our physical surroundings with our religious identities. Rather than live in tension between indulging physical necessity and transcending these needs to attain spiritual meaning, Rabbinic Judaism helps us to attain spiritual meaning by acknowledging that God’s universal dominion is both physical and spiritual, vast and infinite.
Malka Z. Simkovich, “Intimacy on Shabbat: Was It Always a Mitzvah?”, TheTorah.com (21 January 2014) [http://thetorah.com/intimacy-on-shabbat/]