Having been awakened with faith, having zeal, being baptized, and experiencing divine grace, God then hides grace from us, Saint Theophan tells us. This is a most common experience for all serious Christian faithful who seek union with God. It seems that as soon as we have His grace, it is gone. It comes and then leaves. Why is this most sublime feeling allowed to leave us? It seems as if God abandons us.
When this happened to me I felt betrayed, after all, I had accomplished a great thing through my spiritual efforts. Yes, I was proud. If it had stayed with me, this pride would only have grown and I would have remained complacent. But when it left, what did I do? I sought help and was guided to work hard to uncover my deep hidden sinfulness. This involved things everyone else knew about me, but were hidden from my own self-awareness. I gave up my old ways of seeking an spiritual experience through the eastern meditation practice I had long practiced. I started anew in my spiritual path becoming obedient to my spiritual father. Glory be to God for this!
This is why this withdrawal happens. Initially we are encouraged by the experience of His grace, but we still have great pride and need to be humbled. After this initial encouragement, this withdrawal leeds us to further growth through a processes of purifying our heart.
Saint Diadochos tells that grace is working in us without our knowledge,
At the start of the spiritual way, the soul usually has the conscious experience of being illumined with its own light through the action of grace. But as it advances further in its struggle to attain theology (knowledge of God through direct experience), grace works its mysteries within the soul for the most part without its knowledge.
He continues to clarify the two ways that grace works in us - with and without our knowledge: Grace acts in these two ways so that it may first set us rejoicing on the path of contemplation, calling us from ignorance to spiritual knowledge, and so that in the midst of our struggle it may then keep this knowledge free from arrogance. On the one hand, we need to be somewhat saddened by feeling ourselves abandoned, so that we become more humble and submit to the glory of the Lord; on the other hand, we need to be gladdened at the right time though being lifted up by hope... (Philokalia, vol 1, no 69, p 276)
Through this awareness of a direct experience and then its withdrawal, God is nurturing us to complete the course. He wants us to have holy love and for it to become habitual. If He allowed grace to remain ever present to our awareness, we would become satisfied, stuck in our pride and hidden sinfulness, and not continue on our path to perfection.
Saint Diadochos says,
When God recedes in order to educate us, this brings great sadness, humility and even some measure of despair to the soul. the purpose of this is to humble the soul's tendency to vanity and self-glory, for the heart is at once filled with fear of God, tears of thankfulness, and great longing for the beauty of silence.
(Philokalia, vol 1, no 87, p 286)
Saint Diadochus continues, highlighting the way God works for our benefit. , As the soul advances, divine grace more and more reveals itself of the intellect. During the process, however , the Lord allows the soul to be pestered increasingly by demons. This is to teach it to discriminate correctly between good an devil, and to make it more humble through the deep shame it feels during its purification because of the way in which it is defiled by demonic thoughts. (Philokalia, vol 1, no 77, p 279-80)
Saint Marcarius of Egypt also advises us about how God's grace works within us. The spiritual influence of God's grace within the soul works with great patience, wisdom, and mysterious management of the mind, while the man for long times and seasons contends in much endurance; and then the work of grace is proved to be perfect in him. (Fifty Spiritual Homilies, 9.1 p 83)
Knowing God in a way where we experience Him continually and are able to carry out His will is a process. As we gain the ability to do God's will, we again experience his grace, but when we fall back, engage in judging others or become proud of our spiritual advancement for example, this feeling is withdrawn. Not as a punishment but to spur us on to greater and greater growth until we have purified our heart and join in union wtih Him continually. Knowing God is not an event but a lifelong process.