The spiritual maximalism of St. Symeon the New Theologian, evangelical in its basis and mystical in purpose, is the very essence of his catechetical approach, as well as of his public reception in the ecclesiastic society of his time. Far from iniating a peculiar spiritual renewal, St. Symeon gives voice to his personal astonishing experience of the grace of God, which confirms the words of the Gospels regarding the call of mankind to deification. St. Symeon’s struggle is to persuade his audience that real and experienced communion with Christ, through the grace of the Holy Spirit, is not the privilege of the saints of the old times, but an attainable experience for everyone who is determined to radically change his way of life and give maximum priority to the shunning of passions by spiritual guidance and the fulfilment of the evangelic demands.