Prayer, according to St. John Chrysostomos, is a great and mighty weapon, a great possession, a binding of man with God, it is a medicine, a everlasting richness, in which the grace of God flows freely throygh the veins of the soul, an invitation to the eternal life. Prayer compares to the Angels. Man himself, converses with God. “Nothing has its measure”. Nothing is equal to prayer, says the Holy Father. Prayer is a skill, thus it requires practice and continuing effort. It must be made with zealous soul, with deep concentration, so we realize, which direction to take, who we stand before and who we converse with. “Pray without ceasing” St. Paul tells us (Thess. 5. V. 17.). (From the prologue of the book).