1. What is the chief end of man?Man's chief end is to glorify God, and to enjoy him for ever. But I hear Witherington's critique, and I hear because I suspect we on the Reformed side have not been sufficiently articulate in explaining quite what we mean by "God's self-glorification". John Piper, perhaps the most prolific expositor of this doctrine in recent times, uses phrases like "God's loving self-exaltation", which explains where Witherington's question, "Is God a narcissist?" comes from.But I would suggest that this question is better approached from a different direction. The question "Is God a narcissist?" is loaded with all sorts of difficulties as well as a clear rhetorical challenge. But it's directly equivalent to the question "Does God love himself?" This we can understand, because the only response is that this is the wrong question. It isn't so much that God loves himself as that Father, Son and Spirit exist in eternal and mutual love. The Persons of the Trinity love each other, and this love is foundational. The question is the wrong question because we rightly understand love to be something properly directed to someone else, and yet we read that God is love.In a similar manner, glorification, exaltation and praise are things which are properly directed to another. So to ask whether God glorifies himself is to ask the wrong question. Certainly he does, as ample Old Testament demonstrates, but we can say so much more than that. It isn't that God glorifies himself, but that Father, Son and Holy Spirit bring glory to each other .In fact, I believe we can go further still. The fact that Father, Son and Holy Spirit bring glory to each other is precisely because of the love that they share in eternity, since to exalt the other is a supreme act of love. And pushing further still, I would suggest that a doctrine given a rather complicated Greek name, perichoresis , provides the best framework for understanding the Trinitarian form of God's glorification . This is the doctrine that the Persons of the Triune Godhead mutually indwell one another, and seems—although the biblical data are very faint—to suggest that the characteristics of the Godhead flow out of this perichoretic union.For instance, it seems it was Augustine who first suggested that intra-Trinitarian love is founded on the mutual indwelling of the Father and the Son in the unity of the Spirit.
Next, if there be among the gifts of God none greater than love, and there is no greater gift of God than the Holy Spirit, what follows more naturally than that He is Himself love, who is called both God and of God? So while it may be proper to speak of the Godhead as the One who brings all glory to himself, we ought not to speak this way. Instead, it is far better to speak of the mutual glorification of the Persons of the Trinity, whose action in creation was to bring further glory to each other, for as the Apostle Paul writes, "all things were created through [Christ] and for him."  I would tentatively point out that the Scriptures themselves glorify the Father and the Son and were written, as Peter put it, by men speaking "from God as they were carried along by the Holy Spirit." Further lines of extremely helpful discussion could be drawn from Christ's self-humiliation in order to glorify the Father, as the beautiful and well-known paean of Philippians 2 proclaims , but I will leave that as an exercise for the reader. It is enough, I think, to conclude that although our language has at times been deeply unhelpful, it is most certainly the case that:
- the Persons of the Godhead exist in eternal love for each other;
- they express that love in bringing glory to each other, quite possibly the highest way in which they do so;
- Father, Son and Holy Spirit call all creation to join in this life of glorifying God.
 A summary of the dust-up can be found in Brister, "Witherington v. Piper Files", 25-Nov-07. Link.
 Westminster Shorter Catechism, question 1. Link.
 John 17:1. Notice that the Son's highest aim is for the Father to be glorified.
 Wikipedia, "Perichoresis", 28-Nov-07. Link.
 Leithart, "Holiness and perichoresis", 18-Dec-04. Link.
 Augustine, "Of the Trinity", xv 19.37. Link.
 Col. 1:16.
 2 Pet. 1:21.
 Phil. 2:6–11.29-Nov-07: a few spelling and formatting errors were fixed and one sentence (regarding Augustine) was re-worked for sense.