Within their monastery enclosure, monastics live a life of spiritual stillness called hesychasm, working in silence and constant prayer throughout the day, keeping vigil at night, and carefully attending to their thoughts and feelings through inner watchfulness and prayer, while participating continually in the Sacraments and the liturgical life of the Church. At the center of this life lived for Christ is the ceaseless repetition—vocally or silently—of the Jesus prayer: “Lord Jesus Christ, have mercy on me.” This prayer, practiced within the framework of perfect obedience to the monastery’s abbot, brings the grace of God into the disciples’ souls. With patience and perseverance, in time and by the great mercy of God, they attain to the acquisition of the Holy Spirit.
Christ taught this life in His Sermon on the Mount, in His exhortations to be vigilant and take heed, to have absolute faith in God, to avoid cares that cause anxiety, and so on. He often went up on the mountain to pray on His own, not because He needed to, but to teach us this way of life. He Himself urged us to pray in the inner chamber, and when we have shut the door, to pray to our Father Who is in secret (Matt. 6:6).
If one reads the Acts of the Apostles and the Epistles of the Apostles, they will find that the first Christians—imitating the apostolic community of Christ—lived by prayer, common life, inspiration, with all possessions held in common, and they expected the coming of the Kingdom of God, which they experienced as a spiritual reality.
For more on monasticism see the article by Metropolitan Isaiah of Denver, the former President of Hellenic College/Holy Cross Greek Orthodox School of Theology.
Also, see the article by Georgios I. Mantzarides, Professor Emeritus of the Theological School Aristotle University of Thessaloniki (abridged text from the book Images of Athos by monk Chariton); Professor Mantzarides taught Christian Ethics and Sociology and is also a member of the Bioethics Committee of the Holy Synod of the Church of Greece.