Gregory Nazianzen is one of the most influential theologians ever to have lived; his formulation of the doctrine of the Trinity has been foundational to trinitarian thought throughout the centuries - scroll down to hear him preach it! (NB. This is not actually Gregory preaching, but, of course, he was a Scot).

Click here for to read the whole of Gregory's Oration XL.

For a really accessible introduction to the Trinity that shows how relevant and life changing the knowing the triune God is, get yourself a copy of Mike Reeves' new book, The Good God: Enjoying Father, Son and Spirit.