Remember the Lord’s parable about the leaven hidden in the three measures of meal. The leaven does not become noticeable at once, but remains hidden for a certain time, then later on its action becomes manifest, and finally it penetrates all the dough.
So also the Kingdom within us is first kept secret, later it reveals itself, and finally opens out and appears in its full strength. It reveals itself, as we saw earlier, by the involuntary longing to withdraw within and stand before God. Here the soul has no power of its own, but is moved by an outside influence. Someone takes it and leads it within. It is God, the grace of the Holy Spirit, the Lord and Saviour: no matter which you say, the meaning is one and the same. God shows by this that He accepts the soul and wishes to be master of it, and at the same time He makes the soul accustomed to His mastery, revealing its true nature. until this longing appears—and it does not appear at once—man seems to act apparently by himself; and though he is in fact being helped by grace, its action remains hidden from him.
He arouses his attention and forms good intentions to be within himself, to remember God, to drive away vain and evil thoughts, and to fulfil all tasks in a way that is pleasing to God; he exerts himself and strives until he is tired, but has no success at all in this undertaking. His thoughts are distracted, movements of passion overwhelm him, there is disorder and error in his work. All this is because God has not yet revealed His mastery over the soul. But as soon as this happens (and it happens when we are overcome by this same involuntary longing to withdraw within and stand before God), immediately everything within comes into order—a sign that the King is present there.
St. Theophan the Recluse, The Art of Prayer, p.175-176