A few paragraph’s from Fr. Sophrony’s St. Silouan the Athonite.

It was a great moment in the history of human thought and spiritual experience when Descartes pronounced the words, ‘Cogito, ergo sum’ (‘I think, therefore I am’). Another philosopher, one of our day, understood life rather differently, putting it, ‘I love, therefore I am, for I esteem love a more profound motive for searching out the reality of our existence.’ Others might say, ‘I eat, I walk, therefore I am’ – meaning, ‘Everything I do, everything I manifest, is proof of my existence.’

All these formulae spring from a rational reaction to the question, ‘Do I exist?’. But independently even of such a reflection, in the sphere of irrational (self-) consciousness every man recognises that he exists.

Thus there are spiritual states where man has direct knowledge of his immortality, knows for certain that he is a participant in eternal life; when the Holy Spirit, as the Staretz [St. Silouan] expresses it, bears witness to the soul of her salvation. Trying to find the solution to the problems before us is, indeed, work for the wise man. It is the way of life, the way followed by the Church of Christ. Authentic knowledge of Divine being constitutes the wealth of the Church. Blessed Staretz Silouan was rich precisely in this experience of eternal being bestowed on him by the Holy Spirit and in which he put his trust.