Be concentrated without self-display, withdrawn into your heart. For the demons fear concentration as thieves fear dogs.

St. John Climacus

My friends, God does not ask or desire that man should mourn from sorrow of heart, but rather that, out of love for Him, he should rejoice with spiritual laughter. Remove the sin, and the tear of sorrow is superfluous for your eyes.

St. John Climacus

If you find that there is no love in you, but you want to have it, then do deeds of love, even though you do them without love in the beginning. The Lord will see you desire and striving and will put love in your heart.

St. Ambrose of Optina

Only the foolish think that suffering is evil. A sensible man knows that suffering is not evil but only the manifestation of evil and healing from evil. Only sin in a man is a real evil, and there is no evil outside sin. Everything else that men generally call evil is not, but is a bitter medicine to heal from evil. The sicker the man, the more bitter the medicine that the doctor prescribes for him. At times, even, it seems to a sick man that the medicine is worse and more bitter than the sickness itself! And so it seems at times to the sinner: the suffering is harder and more bitter than the sin committed. But this is only an illusion – a very strong self-delusion. There is no suffering in the world that could be anywhere near as hard and destructive as sin is. All the suffering borne by men and nations is none other than the abundant healing that eternal Mercy offers to men and nations to save them from eternal death. Every sin, however small, would inevitably bring death if Mercy were not to allow suffering in order to sober men up from the inebriation of sin; for the healing that comes through suffering is brought about by the grace-filled power of the Holy and Life-giving Spirit. 

Blessed is the man who uses his sufferings, knowing that all suffering in this brief life is loosed on men by God in His love for mankind, for the benefit and assistance of men. In His mercy, God looses suffering on men because of their sins – by His mercy and not His justice. For, if it were by His justice, every sin would inevitably bring death, as the Apostle says: “Sin, when it is finished, bringeth forth death” (James 1: 15). In place of death, God gives healing through suffering. Suffering is God’s way of healing the soul of its sinful leprosy and its death.

St. Nikolai Velimirovich

There is not, never has been, nor ever will be a place on the earth without sorrows.  A place without sorrows can only be in the heart, when the Lord is within it.

St. Nikon of Optina

O, how needful it is that we entreat the Lord to give the soul His humble Holy Spirit! The lowly soul enjoys great peace, while the proud soul is a torment to herself.

St. Silouan the Athonite

What does it mean to take up your cross? It means the willing acceptance, at the hand of Providence, of every means of healing, bitter though it may be, that is offered. Do great catastrophies fall on you? Be obedient to God’s will, as Noah was. Is sacrifice demanded of you? Give yourself into God’s hands with the same faith as Abram had when he went to sacrifice his son. Is your property ruined? Do your children die suddenly? Suffer it all with patience, cleaving to God in your heart, as Job did. Do your friends forsake you, and you find yourself surrounded by enemies? Bear it all without grumbling, and with faith that God’s help is at hand, as the apostles did.

St. Nikolai Velimirovich

Some people tell me that they are scandalized because they see many things wrong in the Church. I tell them that if you ask a fly, “Are there any flowers in this area?” it will say, “I don’t know about flowers, but over there in that heap of rubbish you can find all the filth you want.” And it will go on to list all the unclean things it has been to. 

Now, if you ask a honeybee, “Have you seen any unclean things in this area?” it will reply, “Unclean things? No, I have not seen any; the place here is full of the most fragrant flowers.” And it will go on to name all the flowers of the garden or the meadow. 

You see, the fly only knows where the unclean things are, while the honeybee knows where the beautiful iris or hyacinth is. As I have come to understand, some people resemble the honeybee and some resemble the fly. Those who resemble the fly seek to find evil in every circumstance and are preoccupied with it; they see no good anywhere. But those who resemble the honeybee only see the good in everything they see. 

The stupid person thinks stupidly and takes everything in the wrong way, whereas the person who has good thoughts, no matter what he sees, no matter what you tell him, maintains a positive and good thought.

St. Paisios of Mount Athos

If we want, Christian, to have our heart filled with divine love we must first empty it of the love of this world, its frivolous and sinful customs and then turn our hearts to the one God, our only good and happiness and eternal beatitude.

St Tikhon of Zadonsk

Prayer does not consist merely in standing and bowing your body or in reading written prayers….it is possible to pray at all times, in all places, with mind and spirit. You can lift up your mind and heart to God while walking, sitting, working, in a crowd and in solitude. His door is always open, unlike man’s. We can always say to Him in our hearts Lord , Lord have mercy.

St. Tikhon of Zadonsk

Not every "good" deed is actually good, but only that good deed which is done for the sake of God.  The externals of a particular action are not its essence; God alone sees a person's heart.  We need to humble ourselves, realizing that every good deed is mixed with some passion.

St. Nikon of Optina

Open, O doors and bolts of my heart, that Christ the King of Glory may enter! 

Enter, O my Light, and enlighten my darkness; 

Enter, O my Life, and resurrect my deadness;

Enter, O my Physician, and heal my wounds; 

Enter, O Divine Fire, and burn up the thorns of my sins; 

Ignite my inward parts and my heart with the flame of Your love; 

Enter, O my King, and destroy in me the kingdom of sin; 

Sit on the throne of my heart and alone reign in me, O Christ, my King and Lord!

St Dimitri of Rostov 

The grace of the Holy Spirit which is given mystically to every Christian when he is baptized acts and is manifested in proportion to our obedience to the commandments of the Lord. That is, if a Christian obeys the commandments of the Lord more, grace acts with him more, while if he obeys them less, grace acts within him less. Just as a spark, when covered in the ashes of fire becomes increasingly manifest as one removes the ashes, and the more fire wood you put the more the fire burns, so the grace that has been given to every Christian through Holy Baptism is hidden in the heart and covered up by the passions and sins, and the more a man acts in accordance with the commandments of Christ, the more he is cleansed of the passions and the more the fire of Divine grace lights in his heart, illumines and deifies him.

St. Nicodemus of the Holy Mountain

God is loving to man, and loving in no small measure. For say not, I have committed fornication and adultery: I have done dreadful things, and not once only, but often: will He forgive? Will He grant pardon? Hear what the Psalmist says: "How great is the multitude of Your goodness, O Lord!" 

Your accumulated offenses surpass not the multitude of God’s mercies: your wounds surpass not the great Physician’s skill. Only give yourself up in faith: tell the Physician your ailment: say thou also, like David: "I said, I will confess me my sin unto the Lord": and the same shall be done in your case, which he says immediately: "And you forgave the wickedness of my heart.”

St. Cyril of Jerusalem

The fact that I am a monk and you are a layman is of no importance. The Lord listens equally to the monk and to the man of the world provided both are true believers. He looks for a heart full of true faith into which to send his Spirit. For the heart of a man is capable of containing the Kingdom of God. The Holy Spirit and the Kingdom of God are one.

St Seraphim of Sarov 

The mouth which is continuously giving thanks receives blessing from God. In the heart that always shows gratitude, grace abides.

St Isaac of Syria

Virtue does not consist in many different visible bodily activities, but in a heart that is wise in what it hopes for, and whose actions are accompanied by a right intention.

St Isaac of Syria 

What is it that I love when I love You? Not the beauty of a body or the comeliness of time. Nor the luster of the light pleasing to the eyes, nor the sweet melodies of all manner of songs, nor the fragrance of flowers, ointments and spices, not manna and honey, nor limbs welcome to the embrace of the flesh - I do not love these when I love my God. And yet there is a kind of light, a kind of voice, a kind of fragrance, a kind of foods, a kind of embrace, when I love my God, who is the light, voice, fragrance, food, embrace of the inner man, where there shines into the soul that which no place can contain, and there sounds forth that which time cannot end, where there is fragrance which no breeze disperses, taste which eating does not make less, and a clinging together which fulfillment does not terminate. It is this that I love when I love my God.

St. Augustine of Hippo

Courageousness of heart, and scorning every danger, come from one of two causes: either they are due to hardness of heart, or from an abundant faith in God. The former is accompanied by pride, the latter by humility of heart.

St. Isaac of Syria 

To deny oneself means to give up one's bad habits; to root out of the heart all that ties us to the world; not to cherish bad thoughts and ideas; to suppress every evil thought; to avoid occasions of sin; not to desire or do anything out of self-love, but to do everything out of love for God. 

St. Innocent of Alaska