The dangers of anxiety for the life of the soul

‎"Anxiety is the greatest evil that can befall the soul — except sin. . . . When our heart is troubled and disturbed within itself, it loses the strength necessary to maintain the virtues that it had acquired. At the same time, it loses the means to resist the temptations of the enemy, who then uses his utmost efforts to fish, as they say, in troubled waters.” - St. Francis de Sales