Every Christian knows God in his providential action by which the Christian is led in the particular circumstances of his own life, sometimes having good things for his lot, at other times – as a kind of training – being deprived of them. This latter form of guidance Saint Maximos calls leading through judgment . . .
Everyone knows God in the qualms of conscience he feels for the wrongs he has committed and, finally, everyone knows him in his own troubles and failure – temporary or lasting – in his own illness or that of those close to him that results from certain evils done or as a means of moral perfections and spiritual strengthening; but everyone also knows God in the help that he receives from him in overcoming these and all the other barriers and difficulties that stand in his way. This knowledge helps in leading each man on his own way of perfection.
It is a thrilling, burdensome, painful and joyful knowledge; it wakens within us our ability to respond; it gives fervor to prayer, and it causes our being to draw closer to God.
In this knowledge, our being experiences in practice the goodness, power, justice and wisdom of God, his attentive care for us, and God’s special plan in its regard. In this connection the human person experiences a relation of particular intimacy with God as supreme Personal reality. In this knowledge I no longer see God only as the creator and the providential guide of all things, or as the mystery which makes himself visible to all, filling all with a joy which is to a greater or lesser extent the same in all cases; but I know him in his special care and regard to me, in his intimate relations with me, in his plan whereby, through the particular suffering, demands, and direction that he addresses to me in life, he leads me in a special way to the common goal.
This intimate relationship which God has with me certainly does not remove me from solidarity with others or from obligations I have towards others, towards family, nation, my home, my age, all the contemporary world. But God makes himself known to me through the appeals that he addresses to me especially, so as to stir me up to fulfill my duties, or through the remorse that I feel when I have not fulfilled my own special duties . . .
This is why God puts me in circumstances like those described, and through them makes himself transparent on account of the interest he takes in me. It is especially with this purpose in mind that he is the mysterium tremendum.
The difficult circumstances which pierce our being like nails urge us towards more deeply felt prayer. And during this kind of prayer the presence of God is more evident to us . . . the state of prayer is a condition in which through an increase of sensibility, we apprehend God as a “Thou” who is present . . .
The existential experience of God is combined with the apophatic experience of him [and these two combine] with the knowledge of God as creator and providential guide of the world (cataphatic knowledge) . . .
Through these three kinds of knowledge [cataphatic, apophatic, and existential] the personal interest God shows towards man, together with his mystery and greatness that are beyond understanding, come into relief. Through all three, God is known as lover according to the measure of our love for him and for our neighbor.
Dumitru Staniloae, The Experience of God (Orthodox Dogmatic Theology vol. 1), pp. 117-122.