I like this thought from Gregory of Nazianzus on the abstruse subject of the morrows feast:
"The Old Testament preached the Father clearly, but the Son only in an obscure manner. The New Testament revealed the Son, but did no more than hint at the Godhead of the Holy Spirit. Today the Spirit dwells amongus, manifesting himself to us more and more clearly. For it was not safe, when the divinity of the Father had not yet been ackniowledged, plainly to proclaim the Son; nor, when that of the Son had not yet been accepted, to burden us further - if I may use a somewhat bold expression - with the Holy Spirit.
So, by gradual additions and ascents, advancing from glory to glory, the splendour of the Holy Trinity shines upon the more enlightened. You see illuminations breaking upon us gradually; while the order of theology, which it is better for us to observe, prevents us both from proclaiming everything at once and from keeping it all hidden to the end."
OK, the exegesis in para one is lousy, the man never had an SPCK grant and missed out on the joys of Wainwright on the Trinity in the New Testament. But the gradual dawning of the light, the graciousness of God in the development of doctrine - well, easy to see why I prefet the Cappadocians to St Athanasius.