To wage war only with the sins that make their appearance as actual deeds would be just as unsuccessful as cutting down weeds in a garden instead of digging them up at the root and throwing them out. Sins appear as inevitable outgrowths from their roots, the passions of the soul.
In times of any sorrow, illness, poverty, need, disagreements, and any difficulty, it is better to spend less time in ruminating and talking to ourselves, and more often to turn to Christ our God and to his most pure Mother in prayer, even if it is only a brief one. Through that, the spirit of bitter despondency will be driven away, and the heart will be filled with joy and with hope in God.
Even a pious person is not immune to spiritual sickness if he does not have a wise guide -- either a living person or a spiritual writer. This sickness is called prelest, or spiritual delusion, imagining oneself to be near to God and to the realm of the divine and supernatural. Even zealous ascetics in monasteries are sometimes subject to this delusion, but of course, laymen who are zealous in external struggles (podvigi) undergo it much more frequently. Surpassing their acquaintances in struggles of prayer and fasting, they imagine that they are seers of divine visions, or at least of dreams inspired by grace. In every event of their lives, they see special intentional directions from God or their guardian angel. And then they start imagining that they are God's elect, and often try to foretell the future. The Holy Fathers armed themselves against nothing so fiercely as against this sickness -- prelest.
Peace of soul is acquired by perfect surrender to the Divine Will, without which nothing happens... He, in whose heart humility and meekness are reborn, will find true rest for his soul. He will be satisfied with everything, grateful for everything, peaceful and full of love for everybody. He will judge none and will feel no anger. His heart will be filled with divine sweetness, that is, he will feel in himself the Kingdom of God because God grants His grace only to the humble.
No matter what misfortune might befall you, no matter what unpleasantness might occur, say 'I will endure this for Jesus Christ's sake!' Just say that, and you will feel better, for the Name of Jesus Christ is powerful. Before It, all difficulties abate, and demons disappear. Your annoyance and faintness of heart will abate when you repeat His most sweet Name. Lord, grant unto me to see my transgressions. Lord, grant unto me patience, magnanimity, and meekness.
Meekness and humility of heart are virtues without which it is impossible to inherit the Heavenly Kingdom, to be happy on earth, or to experience inner calm.
He, in whose heart humility and meekness are reborn, will find true rest for his soul. He will be satisfied with everything, grateful for everything, peaceful and full of love for everybody. He will judge none and will feel no anger. His heart will be filled with divine sweetness, that is, he will feel in himself the Kingdom of God because God grants His grace only to the humble.