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.
To act 'according to one’s strength' means to use a little less than necessary both of food, and drink, and sleep... As for food, restrain yourself when you wish to eat a little more, and in this way you will always make use of it moderately.
In no art do the artists judge the result of their work by the tools they use, but they await the work's completion and by it judge the art. Adopting such a practice with regard to food, not placing all your hope on fasting, but fasting moderately and according to the amount of your strength, strive toward mental activity. In this way you can avoid pride and will not spurn God's good works, sending up praises to God for everything.
When the door of steam baths is continually left open, the heat inside rapidly escapes through it; likewise the soul in its desire to say many things, dissipates the remembrance of God through the door of speech, even though everything it says may be good. Ideas of value always shun verbosity, being foreign to confusion and fantasy. Timely silence, then, is precious, for it is nothing less than the mother of the wisest thoughts.
We ought to have the most lively spiritual union with the heavenly inhabitants, with all the saints, apostles, prophets, martyrs, prelates, venerable and righteous men, as they are all members of one single body, The Church of Christ, to which we sinners also belong, and the living Head of which is the Lord Jesus Christ Himself. This is why we call upon them in prayer, converse with them, thank and praise them, It is urgently necessary for all Christians to be in union with them, if they desire to make Christian progress; for the saints are our friends, our guides to salvation, who pray and intercede for us.
When the flesh flourishes, the soul fades; when the flesh has full liberty, the soul is straitened; when the flesh is satiated, the soul hungers; when the flesh is adorned, the soul is deformed; when the flesh overflows with laughter, the soul is surrounded by misfortune; when the flesh is in the light, the soul is in darkness...
What should one do so that the mind might be constantly occupied with God? If we do not acquire the three following virtues: love for God and men, continence, and the Prayer of Jesus, then our mind cannot be completely occupied with God. For love makes anger meek, continence weakens fleshly desire, and prayer draws the mind away from thoughts and banishes every hatred and high-mindedness.
But where does Christ dwell? In pure hearts, hearts that are humble and contrite, there where He is not grieved by doubt or unbelief, by indifference towards Him, Who is God and Savior; there where men do not prefer the temporal sweetness of sin; where the idols of the passions have been chased out; where crude materiality is not preferred to the Kingdom of God, where Christians often turn their thoughts to the heavenly, as those created for heaven, for eternity; there where they seek God's truth, where every day and every hour they are attentive to His commandments. Here is where Christ dwells. And what does He do there? If only we knew (some, of course, do know) what He does in souls worthy of His abiding presence--what rest, comfort and joy He imparts, what paradisical bliss He gives them to experience while still on this earth.
Concerning fasting, do not grieve, as I have said to you before: God does not demand of anyone labors beyond his strength. And indeed, what is fasting if not a punishment of the body in order to humble a healthy body and make it infirm for passions, according to the word of the Apostle: 'When I am weak, then am I strong' (II Corinthians 12:10).
The truth and saving properties of our holy faith are clearly revealed by the fact that not a single Sacrament, not a single faithful prayer are left fruitless in us, but they bring and manifest their power from heaven upon our souls and bodies, cleansing our sins, and giving peace to our souls in accordance with the words of our Savior: 'Come unto Me, all ye that labor and are heavy laden, and I will give you rest' (Mt. 11:28); and delivering us from spiritual afflictions and bodily sicknesses! No, we never pray in vain to the Lord, or to the most holy Virgin, or to the angels and saints, but we receive all that we ask them for, and that tends to our salvation.