I've been going through Everett Ferguson's Backgrounds of Early Christianity (Grand Rapids: William B. Eerdmans, 1993), and I see there are parallels between Greek purity rules and those in the Pentateuch.
Ferguson quotes the following "rules of purity for visitors to the temple of Athena at Pergamum":
"Whoever wishes to visit the temple of the goddess, whether a resident of the city or anyone else, must refrain from intercourse with his wife (or husband) that day, from intercourse with another than his wife (or husband) for the preceding two days, and must complete the requires lustrations. The same prohibition applies to contact with the dead and with the delivery of a woman in childbirth." (175)
A few pages earlier, Ferguson offers the following description of the Greek priesthood:
"The essential qualification [for priesthood] was that one 'know how' to approach the deity. But the regulations of particular cults specify other requirements. The most commonly expressed requirement is freedom from physical defects or infirmity. In the civic cults it was also necessary that one be a citizen. The conditions relative to age were quite variable. There are several cases on record of priesthoods held by children. This may be related to a fairly frequent demand for celibacy during the term of office. The requirement was not a matter of morality, but of ritual purity, and the assigning of priesthoods to the elderly or the very young conforms to the ancient view that sexual functions were ceremonially defiling (cf. Lev. 22:4-6)."
Similarly, in the Torah, we see a clear attempt to separate the holy from sex (Leviticus 15; 22:4-6), death (Leviticus 21; Numbers 5:1; 9; 14), and childbirth (Leviticus 12).
In a discussion I had with James McGrath under his post, What Do You Say That I Did?, McGrath states the following:
"The sacrifices that ancient Israel practiced did not originate with them. The texts from Ugarit have almost precisely the same terms we find in Leviticus. And so I wouldn't say there is anything one has to cling to in the sacrificial rituals in order to make sense of how we relate to God."
If the sacrifices and purity system in the Torah did not originate with Israel but were practiced by other nations as well, can we say that they have deep religious significance for Jews and Christians? If the biblical authors did not come up with the separation of the holy from sex, death, and childbirth, can we attach to that concept a meaning that is specific to Judaism and Christianity? Can Jews and Christians find spiritual value in rituals that are practically universal?
I've often connected Israel's purity regulations with Genesis 2-3. After Adam and Eve fell, death entered the world. Pain accompanied childbirth. Sex became corrupted, as the woman's desire became for her husband, and he ruled over her. I thought that the purity rules sought to respect a time when things were different--purer, if you will. But can I say that the authors of the purity regulations had Genesis 2-3 in mind, when other cultures without the Eden story had similar regulations? Maybe the connection is still valid, if Genesis 2-3 is based on the purity regulations rather than vice versa.
God may have copied the rituals for some reason, with the intention to teach Israel a lesson. The real ultra-conservative types (e.g., E.W. Bullinger) would maintain that God gave the earliest humans a religion, which became corrupted as time went on. Bullinger says that's why the Babylonian epic Enuma Elish resembles Genesis 1: Enuma Elish is a corruption of the true story of creation that was passed along before Israel came to exist as a nation. And Bullinger may assume that the same thing applies to the sacrifices: God gave the earliest people rules for sacrifice and purity, as we see with Cain and Abel (Genesis 4) and Noah (Genesis 8:20-21). In a Bullinger-type model, their descendants spread these rules to various regions, and that would explain why so many nations have customs similar to those in the Bible.
Maybe, but there are also differences. According to Ferguson, there were Romans who sacrificed pigs (177), yet Noah and the Israelites offered only clean animals (Genesis 8:20-21).
Can anthropology help us find a universal religious significance in cross-national purity rituals? Maybe nations want to protect the holy from unseemly or chaotic events such as death and childbirth. As far as sex goes, I don't know. Perhaps humans respect the power of sex, or believe that men give up a piece of their life when they emit semen, or view sex as an activity capable of corruption, or want to restrict sex to a particular place, or see sex as too messy to associate with the sacred. I don't know.
I have another issue: Paul talks about temple prostitutes in I Corinthians 6:15-16. Apparently, not all Greek cults tried to divorce sex from the realm of the sacred!