At our last Newfrontiers Leadership training we looked at Haggai as part of a study on the prophets and prophetic. I've been camped out there a bit since then with the help of Bob Fyall's work.
Bob Fyall's BST The Message of Haggai & Ezra. And two mp3s of the same material - mp3 Haggai (part 1) and mp3 Haggai (part 2)
more audios from Rutherford House. ht: Dave Kirkman
Haggai is a great little gospel book. (though that's true of the whole Old Testament however many Biblical Theology myths might abound.) Haggai's concerns seem to centre upon God's presence with his people, the immediacy of his word to them, with an eye to a glorious future and David's throne. Haggai surely knew what was coming. Much to ponder.