Icon of St. Silouan the Athonite There is a big distinction between merely believing that God exists, seeing Him in nature or in the Scriptures, and knowing the Lord by the Holy Spirit.St. Silouan the Athonite
Troparion for St. Silouan

By prayer thou didst receive Christ for thy teacher in the way of humility, and the Spirit bore witness to salvation in thy heart. Wherefore all peoples called unto hope, rejoice in this day of thy memorial, O sacred Father Silouan. Pray unto Christ our God for the salvation of our souls.

Mind in Hell Excerpt

The passage from Archimandrite Sophrony also clarifies the phrase 'keep thy mind in hell and despair not', showing how the struggle against pride is difficult, though an important part of the spiritual life (from St. Silouan the Athonite, page 210).

Keep thy mind in hell, and despair not. What does it mean - to 'keep the mind in hell'? Can it be that we are to use our imagination to conjure up circumstances for ourselves similar to those figured in some primitive painting? In this instance, no. Father Silouan, like certain great Fathers - St. Antony, St. Sisoë, St. Makarios, St. Pimen - during his lifetime actually descended into the darkness and torments of hell They did this not once but over and over again until their hearts were so permeated that they were able to repeat the movement at will. They took refuge in it when passion - especially that most subtle of passions, pride - reared its head.

The struggle against pride is, in fact, the final stage in the battle against the passions. To begin with, the ascetic must wrestle with the greater passions of the flesh, then with irritability and, finally, pride. This last combat is undoubtedly the most painful of all. Taught by long experience that pride leads to loss of grace, the ascetic consciously descends into hell where every passion is 'seared with a hot iron'.