Enter God's Illuminated Darkness
To fail to grasp the importance of the 'cloud' or the 'overshadowing' of God in the New Testament not only deprives man of a richer understanding of how God communicates and interacts with us, but also provides for a serious loss in the understanding of an important concept in mystical theology (i.e., daily prayer).
"Let us run with confidence and joy to enter into the cloud like Moses and Elijah, or like James and John. Let us be caught up like Peter to behold the divine vision and to be transfigured by that glorious transfiguration. Let us retire from the world, stand aloof from the earth, rise above the body, detach ourselves from creatures and turn to the creator, to whom Peter in ecstasy exclaimed: Lord, it is good for us to be here" (from a sermon on the Feast of the Transfiguration by St. Anastasius of Sinai).
While man coming to the light of faith is a first step, there is another intervening step toward union with God in prayer that involves a kind of darkness. That is why St. Gregory of Nyssa (an enormous figure in the history of the Church, especially for the development of mystical theology) was clear about the importance of going beyond the light, and into the total darkness of God.
"For leaving behind everything that is observed, not only what sense comprehends but also what the intelligence thinks it sees, it keeps on penetrating deeper until by the intelligence's yearning for understanding it gains access to the invisible and incomprehensible, and there it sees God. This is the true knowledge of what is sought; this is the seeing that consists in not seeing, because that which is sought transcends all knowledge, being separated on all sides by incomprehensibility as by a kind of darkness" (The Life of Moses, #163).
For those who have had the experience of crossing into the divide of the comingled reality of divine and human like Moses, Mary, Peter, James, and John, they too know and testify to the truth that the All-Holy Trinity is constantly reaching out toward us in that dark cloud, and inviting us into it through prayer.