Seitz demands that Christ's teaching has to be coherent, that only with difficulty can the Holy Spirit inspire diversity, and that at Pentecost the Holy Spirit overcomes not endorses diversity. A new truth does not mean a diversity (though one wonders what else a new truth can mean if there is also an old one).
For Seitz, what is new is not new at all:
What is new is capacitated understanding, which takes the form of enlarged content only because of this. What Jesus has taught but was not grasped in his earthly life is to be grasped...
I would comment to all this as a friend of Unitarianism. As sharing a Unitarian perspective, I know very well the difference between unity and uniformity. From my and its perspectives, there is, first of all, nothing holier than thou about the Bible. It is not the same as history, and indeed is problematic regarding history. Nor is it the same as ethics. So the first question regarding its theological insights is whether they are the only accounts of what happened, and I rather doubt that Pentecost was some one off event, but made into an event and given a spin of being the opposite of Babel. It is the early, particularly Gentile, Church asking when did it start in the sense of when this resurrected Christ was apparently no longer seen by anyone, when the line was drawn in the sand by the invention of an Ascension before it so that the Church leaders legitimately took over and were then were guided by something else and yet of divine authority than a returned Christ.
Given the 'happy birthday' story, the next part is that it is quite possible for different things around the world to be the case, and be partly understood, and for them to be holy. By their fruits they are known. There are differences of Scriptures like the Bhagavad Gita, the Tanakh, the Buddhist Sutras and the Christian New Testament. They are all various and cultural, communal and part of human inspiration, and they all possess truths. How do we know? Well, we don't, but if they help, that's a good sign.
So where they are not helpful, they are not good, not likely to be holy (we can so classify), and to be rejected. So if two people consent, love one another, and express it, and that draws them closer, then it is good; if a Scripture says it is not good, then the Scripture is to be rejected, not what is good.
But clearly Seitz is making his claims as a Christian, so he needs countering by one of his own. And for such I go to a book sent to me some time back by Andrew Linzey and a book that comes from 1988. It is Clarke, P. A. B., Linzey, A., Moses, J. (1988), Theology, the University and the Modern World, London: Lester Crook Academic Publishing. I refer to Andrew Linzey's chapter, 'On Theology', 29-66.
I do know that Andrew still has similar views about the Holy Spirit as in the book, but I don't know if they are the same views or more or less radical than now. The arguments stand as written then.
He writes in favour of the Spirit that is for both tradition and discovery. There is an objection: that those who focus on pneumatology (the work of the Holy Spirit) detract from God's central revealing work in Jesus Christ. In response Linzey says:
The difficulty with this suggestion it seems to me lies in the way in which the 'centre' of revelation is regarded as the limit of revelation. It necessarily demands that we neglect the biblical insight to the effect that there is something new to be learnt. (Linzey, 1988, 51)
He argues a little further on:
Here, once again, is the Barthian dilemma. It involves paying lip service to the Trinity and trinitarian formulae but actually operating a binitarian approach to theology. For if we place absolute or near-absolute authority of what is given in Christ to the neglect of the third person of the Trinity, namely the Spirit, we actually weaken, seriously, if not terminally, the fullest understanding of God's self-presentation. (1988, 51)
An example of what is new and "fundamental" for Linzey, to be added to the work of Christ, is that there can no longer be a division between the 'sacred' and the 'secular', and this is because of the immanence of the Spirit in the whole world.
There is no sphere in which the Spirit is absent. There is no secular history. (51)
The Spirit can be derided and rejected, but is never absent. God has made the world one in the Incarnation and the witnessing of the Spirit is a work of illumination for every generation (51). Linzey goes on to argue in an anti-dualist direction, so that matter devoid of spiritual power is the road to "radical dehumanisation" (52).
In extending the argument, Linzey goes on to state that grace is operative and available to us in our situations (53) where human freedom is positively affirmed. The creation awaits to be raised to new heights, says Paul. And so a primary and decisive finding on the pneumatological perspective is that the world order is unfinished and humans are invited to participate towards its completion (54). Mechanical and objectified understandings of nature are impoverished, and we can help the world's liberation all of which needs ethical and theological discernment (54).
The world does not stand still; it is dynamic (55) and we come face to face with the fruits of our behaviour. Given that Jesus did not give detailed rules and prescriptions, we should instead follow the example of healing, service and costly loving towards the whole creation (55). It comes down to compassion, as well as sensitivity, forgiveness and understanding (55).
Moralising makes us inevitably like the Pharisees (55) and it needs a radical approach to Christian ethics so that we are more "truly" Jesus-like and "fully and properly" traditional (56).
Linzey wants less focus on the past and more on the present and future, movement from renewal of the Church towards renewal of the world, and the Spirit being grasped as less of a possession and more as a gift to the entire creation, moving from the human to the all, and moving from uniformity to diversity and complexity (56). All this means living dialectically, between what is given and what is experienced anew and between creation as is and what can be, and between tradition and discovery (56).
Linzey identifies Anlgicanism as living in the dialectic (57), neither papalist nor biblical Protestant (said David Jenkins, the one time Bishop of Durham, in 'The Nature of Christian Belief', to his General Synod on July 16, 1986). Linzey in 1988 saw that theological diversity was under serious threat - a point surely that has been realised under the present Archbishop of Canterbury. Individuals should be able to explore and share "without intimidation or frustration" (57).
Regarding diversity, Jesus was surely pacifist but Anglicans can hold a variety of views on such a basic matter (58). If there can be diversity on this, then there can be "diversity everywhere" (58).
...the same freedom of diversity must be legitimate on each and every moral issue... It really will not do for some Christians to speak as though here is a legitimate diversity of view on such questions as nuclear war, but a 'line' hat must be followed on such issues as capital punishment, abortion, homosexuality, divorce and the rest. (58)
Andrew Linzey does refer back to Christ:
But the great mistake here [regarding uniformity of opinion] is to suppose that the 'mind of Christ' is monochromatic and that correspondingly there is one view on every moral issue that the Lord wishes for each individual Christian or for the whole Church. Such an understanding of things presupposes what was not even actually true of the historical Jesus. (59)
From time to time majority verdicts can be offered to the world, although the General Synod might realise its own historical peculiarity to temper its moral judgements (no reference here to the Anglican Communion) (59). Christian leaders should do no other than represent the diversity of Church members (60).
Unifying through uniformity does not work, and often the opposite is the case (60). David Jenkins (again, same speech) stressed the greater importance of being together over agreeing when in the Living Body (61).
Thus the argument is made against the uniformity position of a Christopher Seitz, and for the more culturally sensitive view of a Katherine Jefferts Schori of today, and definitely against the bureaucratic view of a Rowan Williams, that seems to be devoid of any spirit except a managerial one of an imagined para-Church.
My view is different in perspective from Andrew Linzey's, but I come to the same conclusion. For me, the quantum world and the bigger world is full of contradictions that exist together. Our cultural life is full of shifting paradigms and new discoveries. Theology is to be addressed about the present, and it is a combination of speculations about the divine - how even to understand the divine - and the ethical charge involved. Tradition and texts are limited: we read texts today where we are, and tradition is simply the inherited ancient forms of religious words with and histories and communities that express these present day religious conundrums.
The Seitz position is wooden, ridiculously biblicist over all other texts, past-orientated, inflexible and about uniformity. It is ridiculous: for ethical reasons it should be contested and, ultimately, ignored.