…our Lord has commanded us to practice constant prayerful watchfulness over ourselves…”Watch and pray, lest you enter into temptation,” said the Lord to His disciples. “And what I say to you, I say to all: Watch!” (Mark 13:37)
St Hesychius of Jerusalem defines vigilance (watchfulness) thus: “Sobriety or vigilance is the way to every virtue and commandment of God”…vigilance comes from the most careful and constant study of the Gospel commandments, and consequently of the whole of sacred Scripture. Vigilance strives unremittingly to abide by all the Gospel commandments in one’s actions, words, thoughts, and feelings….it unceasingly cries to God for help with the most vigorous prayer….
“It gives the person who practices it a sure knowledge of the incomprehensible God, so far as He can be comprehended, and a solution to divine and hidden mysteries….it is really purity of heart, which, on account of its greatness and value, or to speak more accurately, on account of our listlessness (acedia), is now very rare among [us].”
“Vigilance is constant silence of the heart, free from all thoughts, always unremittingly and constantly calling upon Christ Jesus, Son of God and God, breathing Him alone, courageously fighting with Him against the enemies, confessing to Him Who alone has power to forgive sins….vigilance is a firm control of the mind…”
~Ignatius Brianchaninov
Prayerful Life 