To pray ceaselessly does not mean solely to read prayers, to do prostrations and to go to church. Things aren't like that. We can pray ceaselessly always and wherever we find ourselves. The only thing that we need is for our heart to have a prayerful disposition. It should be humble and to ceaselessly mourn for its unworthiness and sinfulness. Full of fear [or awe] before the grandeur of God, Whom we insult with our sins. If our heart is thus, then we will always be in prayer, at work and at home.
-St. Luke the Surgeon