When we speak of a spirit of vigilance (or watchfulness), we mean a habit of attentiveness to our spiritual wellbeing. Mindful of the words of the Apostle, “Be sober, be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour” (1 Pet 5:8), and of our own weakness, guard our soul like a prudent householder guards his possessions, or a stock trader monitors his positions.