…we must most carefully look after the field of our heart, lest the tares of evil, slothfulness, luxuriousness, self-indulgence, unbelief, avarice, envy, hatred, and others, should grow within it; we must daily weed the field of our heart – at least, at morning and evening prayers, and refresh it by salutary sighs, as by healthful winds, and water it with abundant tears, as by early and late rain. Besides this, we must by every means implant in the field of our heart the seeds of the virtues, faith, hope in God, and love for God and our neighbor, fertilize it with prayer, patience, good works, and not for a single hour remain in complete idleness and inactivity, for in times of idleness and inactivity the enemy zealously sows his tares. ‘While men slept, the enemy came and sowed tares among the wheat and went his way’ (Mt. 13:25).
St. John of Kronstadt