Who is Unaware of the Stream?
You would be a blasphemer if you were to say that every believer receives and possesses the Spirit without knowing or recognizing the fact.
Yes, you would! You would be accusing Christ of lying when he said: ‘The water that I shall give will become in him a spring of water welling up to eternal life.’ and again: ‘Out of his heart shall flow rivers of living water.’ [John 4:14 & 7:38] When a spring wells up, when rivers gush out from a spring, how is it possible to look at it and not to recognize it?
If all that were to happen without our knowledge, clearly we should not have the slightest idea of eternal life that flows from it and dwells in us, nor should we be able to see the light of the Holy Spirit. We should remain like the dead, blind and unconscious. Our hope would be vain, our efforts useless.
But it is not so, not at all! The Father is light, the Son is light, the Holy Spirit is light: one light, timeless, indivisible, inconfusible, eternal, uncreated, illimitable, invisible, lacking nothing, above and beyond all things, a light no one can ever behold without first being purified. And by contemplating it, we can receive it.
Simeon the New Theologian
Theological and Ethical Treatises, 10, 501ff. (SC129, pp.297ff.)
One Heart that Seems Two
How is it possible for sin and grace to dwell in the same heart, as if there were two different hearts?
The illustration of a fire may help. If you have a fire below a vessel and you put some wood on it, the fire flares up and the water in the vessel heats up and boils. But if you fail to put more wood on the fire it begins to fade gradually and goes out.
In our hearts is the heavenly fire of grace. If we pray and meditate on the love of Christ, we add wood to the fire and our hearts burn with longing for God.
If, on the contrary, we are negligent and give our attention to worldly affairs, vice enters the heart, takes it over and torments us.
Nevertheless, the heart remembers the peace which it tasted earlier and begins to repent, to direct itself afresh towards God. On the one hand, then, peace is brought nearer, on the other, we are seeking it fervently in prayer. It is like stirring the fire which is warming the heart.
The vessel of the heart is very deep, so deep that the Bible says God searches the abyss of it. If a person deviates from the way of God’s commandments, he puts himself under the power of sin. And because the heart is a deep abyss, sin goes right down into it in order to take over its territory. So it is necessary for grace also, slowly, to descend to those depths.
Homily 40, 71ff. (PG34, 765ff.)
~ Thomas Spidlik, Drinking from the Hidden Fountain, A Patristic Breviary: Ancient Wisdom for Today’s World