To answer my own question about whether Satan came from Seth, according to 
the "Dictionary of Deities and Demons in the Bible" (K. Van Der Toorn, B. 
Becking, P. Van Der Horst), it seems that Satan does not come from Seth. 
Among other things, the entry on Satan says that the root "STN" is not 
evidenced in any of the cognate languages in texts that are prior or 
contemporary with its occurances in the Hebrew Bible... the meaning of the 
noun "satan" must be determined solely on the basis of its occurances in the 
Hebrew Bible, where it occurs in nine contexts. In five it refers to human 
beings, in four to celestial beings. When used of human beings it is not a 
proper name but rather a common noun meaning 'adversary', either in a 
polemical or a military sense, or 'accuser' when it is used in a legal 
context. In the celestial realm there is only one instance where 'satan' 
might be a proper name. In the other three contexts it is a noun meaning 
'adversary' or 'accuser'. ..

Although the noun 'satan' has no cognates in texts that are prior to or 
contemporary with the biblical texts in which is occurs, there are in 
Akkadian three legal terms meaning 'accuser' that can have both terrestrial 
and celestial referents. These terms are 'bel dababi', 'bel dini', and 'akil 
karsi'. Each can refer to a human legal opponent or to a deity acting as an 
accuser in a legal context and this each term functionally parallels the 
noun satan even though there is no etymological realtionship...... Standing 
behind the idea of deities assuming legal roles with respect to earthly 
happenings is the well known idea of the divine council acting as a 
judiciary body...

The noun satan is used of a divine being in four contexts in the Heb 
bible... as a celestial messenger of God the 'mal'ak yhwh', described as a 
'satan'.... This heavenly being who acts as a 'satan' in Numbers 22 has very 
little in common with later conceptualisatings of Satan. He is Yahweh's 
messenger, not his archenemy and acts in accordance with Yahweh's will 
rather than opposing it. Indeed, Yahweh's messenger here, as elsewhere in 
the Heb bible is basically a hypostatisation of the deity, hence... the real 
satan / adversary in Numbers 22 is none other than Yahweh himself.

Later on in Job we have the satan challenging Yahweh about Job's piety... 
then more examples, blardy blah... Then I look up the entry on Seth, no 
mention of being related to satan... more interested in talking about red 
hippopotami,.. Seth is identified with Baal... Teshub... Typhon... perhaps 
the confrontation between Yahweh and Behemoth is patterned upon Horus and 
Seth... tentative parallel between Behemoth and Seth...

And, no - indeed it seems from consulting only one book (feel free to 
correct me on this from other sources) that Seth is not related to Satan at 
all. (Why did I ever think he might have been? Shrug, I dunno. Must have 
been that whole "Set is more authentic than the Church of Satan's "Satan" 
that I heard from TOS members many years ago... I think I must have thought 
that the two figures were related, way back...)


~Caroline.