Today is the feast of Saints Basil the Great and Gregory Nazianzen, Doctors of the Church. From Basil's On the Holy Spirit (Chapter 9):
Now the Spirit is not brought into intimate association with the soul by local approximation. How indeed could there be a corporeal approach to the incorporeal? This association results from the withdrawal of the passions which, coming afterwards gradually on the soul from its friendship to the flesh, have alienated it from its close relationship with God. Only then after a man is purified from the shame whose stain he took through his wickedness, and has come back again to his natural beauty, and as it were cleaning the Royal Image and restoring its ancient form, only thus is it possible for him to draw near to the Paraclete. And He, like the sun, will by the aid of your purified eye show you in Himself the image of the invisible, and in the blessed spectacle of the image you shall behold the unspeakable beauty of the archetype. Through His aid hearts are lifted up, the weak are held by the hand, and they who are advancing are brought to perfection. Shining upon those that are cleansed from every spot, He makes them spiritual by fellowship with Himself.
From Gregory's Oration 45:
It is now needful for us to sum up our discourse as follows: We were created that we might be made happy. We were made happy when we were created. We were entrusted with Paradise that we might enjoy life. We received a Commandment that we might obtain a good repute by keeping it; not that God did not know what would take place, but because He had laid down the law of Free Will. We were deceived because we were the objects of envy. We were cast out because we transgressed. We fasted because we refused to fast, being overpowered by the Tree of Knowledge. For the Commandment was ancient, coeval with ourselves, and was a kind of education of our souls and curb of luxury, to which we were reasonably made subject, in order that we might recover by keeping it that which we had lost by not keeping it. We needed an Incarnate God, a God put to death, that we might live. We were put to death together with Him, that we might be cleansed; we rose again with Him because we were put to death with Him; we were glorified with Him, because we rose again with Him.