There is a sin which is always 'unto death' [1 Jn 5:16]; the sin which we have not repented. Even a saint's prayers will not be heard for the unrepented sin. The person who repents correctly does not imagine that his sins are cancelled through his own effort; but knows that through this effort he makes peace with God.
Keep your mind from malicious thoughts of your neighbors, knowing that such thoughts are hurled by diabolical power, to keep your mind from your own sins and from seeking.
We should not miss any chance to us to say the Jesus Prayer. We must not let our mind wander in vain things. In saying the Jesus Prayer one's mind finds rest and joy. It is like small children who for the whole day run around, shouting and playing and hitting each other. But the one thing that gives them rest and great joy is when at night they find themselves in their mother's arms. This way also one's mind instead of being scattered about, out to be devoted to mental prayer.
The Lord commands all men to repent (Matt. 4:17), so that even the spiritual and those making progress should not neglect this injunction and fail to give attention to the smallest and most subtle errors.
If you wish to be saved and 'to come unto the knowledge of the truth' (I Tim. 2:4), endeavor always to transcend sensible things, and through hope alone to cleave to God. Then you will find principalities and powers fighting against you (Eph. 6:12), deflecting you against your will and provoking you to sin. But if you prevail over them through prayer and maintain your hope, you will receive God's grace, and this will deliver you...
He who wants to cross the spiritual sea is long-suffering, humble, vigilant and self-controlled. If he impetuously embarks on it without these four virtues, he agitates his heart, but cannot cross.
Joseph was amazed as he saw what was supernatural. He understood, O Virgin, the rain upon the fleece In thy conception without seed. And he understood the bush that burned without fire and was unconsumed, And Aaron's rod, which blossomed. Indeed, thy betrothed and guardian cried out to the priests: 'A virgin gives birth, and after the birth remains a virgin.'
It is as necessary for a man to say the Jesus Prayer as it is for a ship in danger to send out steadily the S.O.S. signal: Lord Jesus Christ have mercy on me.
The proof of authenticity of the spiritual condition of a father confessor is, that while he is very strict with himself, he is very lenient with others and does not use the canons of the Church like cannons against them.
The late Athonite Father Tikhon used to say: The prayer, 'Lord Jesus have mercy on us' is worth one hundred drachmas, but 'Glory to God' is word one thousand. Glorifying God is more valuable than anything else, because in the first instance, people often say the Jesus Prayer when needing something; but when one glorifies God in the midst of suffering, it is an ascesis.