Thanks to everyone who commented on my Trinity post.
In reading and reflecting on the comments I have realised that it is deficient to write about Trinity without including Incarnation. Or, put another way, I have confused Trinity and Incarnation.
In the Trinity post I referred to a song with a line that states that Jesus gave up his glorious throne. I have not found a verse in Scripture that explicitly states this same idea. What I have been been reminded of today is Wesley's thought: "He left his Father's throne above,- So free, so infinite his grace- Emptied himself of all but love-"
My problem with the two songs is as much a problem of christology as it is theology.
In the Incarnation (John 1:14, Phil 2:5-11), God the Son revealed another form of God's glory (John 13:31,32; 17:1-5). In coming from the Father the Word's "throne" moved with him and he was "enthroned" as king by being lifted up on the cross. The Post-Reformation Reformed tradition understood this in terms of a fairly well developed and subtle understanding of Christ the Mediator, the Chalcedonian God/Man (see e.g. WCF VIII). In trinitarian terms God the Son never gave up his throne. Christ the Mediator was lifted up as the Mediator King over all of God's creation. He was exalted in the heavenly realm. And he will hand over a new kingdom to God the Father (1Cor15:24).
Palm Sunday is coming up... sermon fodder for you all.