Commentators unanimously agree that the "days of Noah" parallel points to a world engrossed in ordinary life. People will be eating, drinking, and marrying, not necessarily in sinful excess, but with what John Calvin calls a "brutal indifference" to spiritual realities. This normalcy creates a false sense of security, making Christ's return utterly unexpected for the unprepared. The warning is that lawful activities become dangerous when they distract from spiritual watchfulness.