I was pleased to read Lita Cosner's paper "Christ as the last Adam..." in Creation 23(3) 2009. I hope it is the forerunner of more theological work on matters related to creation.
She quoted Barrett's consideration of the unimportance of the historicity of Adam, and rightly, to my mind, disagreed with it.
I fear that Barrett's sentiments are widely held by Christians, if without clear articulation; that is, I think they are held unconsciously by many people, lead by those theologians who do make their case clearly.
There is a thread running through much of Western theology that seemingly rests on a view of the world that is perversely not biblical. Why I say this is that I read the Bible itself as displaying a 'concrete realist' regard for the world and relations within it. Much theology is in debt to some form or other of philosophical idealism: the upshot of idealism is that one seems to be able to hold one set of axioms applying to the real world where we live and shop (try being an idealist in the supermarket), and refer to another set with application only to a world (the 'ideal' world) whose intersection with this world is purely verbal, or ideal, to allow the idealists to be consistent without disconforming pressure from the world he/she moves around in.
Idealists, particularly theological ones, would seem to be able to believe any number of contradictory things before breakfast, and particularly in theology can believe that the Bible at once has God creating, and at the same time the cosmos bringing itself into being, but argued from differing premises without relinquishing the final common relationship.
I don't think that this stands up to biblical scrutiny, let alone logical analysis.
1. He refers us to the Genesian creation account as basic to the interplay of God and man and to remind us that death and sin were not part of the creation. Rather, they are the result of a breach in the relationship between God and his image-bearing creation, man (the interplay gone wrong) and therefore as not inherent in the creation and thus are theoretically correctable! In Christ, of course, they are actually corrected and will be shown to be corrected in the new creation. If they were inherent, then we are stuck with them (and stuck with death, contradictorily from him in whom is life: John 1:4 and on whose creation death is an intruder: Gen 2:17 in the light of Gen 1:26a and 1 Cor. 15:26!).
2. He reminds us that Adam's history, including the fall and thus sin, Christ, and our experience today (his day...our day by induction) are ontologically contiguous. There is no idealist breach in the coordinates of their contiguity; to suggest that there may be ontological discontinuity between them would suggest that reality is other than revealed in the Bible, that there are elements to it that are either not revealed to us, or might be also 'given' and independent of God. Such elements might introduce something between God and man other than Christ (some 'principle' such as may be required by theistic evolution), or tell us that there is more to creation (that which will have an influence on us) than is shown between God and his creation as explained in the Bible...but how would or could we know...it takes us to the endless and fruitless speculation that has often dogged Christian theology with mysticism, for example, to retain this premis of convenience.
2a (or maybe 3). He must needs reference the creation as from God's hand by God's will and done by his word as also sharing time and space coordinates that place it in the same structured reality as that we occupy, and in the same terms as our experience: that is, the events that constituted creation are events as we know events, and do not, probably cannot, refer to another type of event that does not have the same time-space participation that is had by events that follow from will as we know them. This also indicates that our relationship with God, as personal, is personal in equivalent terms to other relationships: our engagement with God, through Christ, is real and substantially concrete; it is to have effects in our life and is not just an 'idea' with no relational or existential consequence within the concrete terms of our world.
The converse, that Barrett would have us entertain, must, I think, undo all this.
But it is not only Barrett who suggests that we need to take Genesis, and the way it frames reality, differently from how we frame the everyday world. Almost every theologian who wants to accommodate the dictates of materialism must do the same thing; perhaps unwittingly, but maybe not.
Discontinuity between the reference frames necessarily flows from denial of the congruence of the Genesis 1 text with the world it seemingly has in its sights. But the discontinuity is self refuting, at least at some level, because it cannot make reference to anything that would sustain the discontinuity apart from a view of the world which at the outset denies the biblical world-conception (hardly a commendation for an approach to the Bible) and has more in common with a paganistic removal of the creator from our world of interaction, or with materialist failure to accommodate the non-material at all.
So, is the choice then that Barrett and his ilk must entertain an imagined world to mount their criticism of the historicity of Adam and hope they maintain a Christian theology, or reject the Bible in the terms in which it couches itself, and therefore ask as to believe them with no adequate basis for such belief, but in doing so render such a theology un-Christian and counter-biblical.