Avoid duplicity, that is, do not let your heart be divided between attachment to God and attachment to earthly things, 'You cannot serve God and mammon' (Mt. 6:24); cling to God alone, put your trust in Him alone; for the Devil, by inciting us to duplicity, seeks himself to gain possession of our heart, which is single and indivisible.
John of KronstadtOur wickedness shall not overpower the unspeakable goodness and mercy of God; our dullness shall not overpower God's wisdom, nor our infirmity God's omnipotence.
John of KronstadtEvery man on earth is sick with the fever of sin, with the blindness of sin and is overcome with its fury. As sins consist mostly of malice and pride, it is necessary to treat everyone who suffers from the malady of sin with kindness and love. This is an important truth, which we often forget. Very often we act in the opposite manner: we add malice to malice by our anger, we oppose pride with pride. Thus, evil grows within us and does not decrease; it is not cured - rather it spreads
John of Kronstadt