Gal 3.16 Seed Messiah
For me, the solution to many of the issues raised here
is at the same time quite simple if also quite "mysterious."
Paul clearly has a complex concept of "Messiah" which includes
corporateness ("the messianic body" to which "believers" belong)
as well as singular identity (Messiah as head). "Seed" has the
same range, and Paul clearly knows the collective sense since
he states a bit later "you are all the seed, children of promise"
(or some such). So the singular seed, Messiah Jesus, is but one
dimension of the corporate messianic seed, which includes all
those who share the messianic sufferings/woes, live by the
messianic law, etc. Schweitzer called it Pauline mysticism;
and it seems to be a natural product of Paul's Jewish eschatological
orientation, his hermeneutical commitments, and his personal
experience. In the messianic context, he died to live.
Bob Kraft, UPenn