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.
No Christian believing rightly in God should ever be off his guard. He should always be on the look-out for temptation, so that when it comes he will not be surprised or disturbed, but will gladly endure the toil and affliction it causes, and so will understand what he is saying when he chants with the prophet: 'Prove me, O Lord, and try me' (Ps. 26:2 LXX). For the prophet did not say, 'Thy correction has destroyed me,' but, 'it has upheld me to the end' (Ps. 18:35 LXX).
Hence, in whatever state a person is, he sometimes finds himself making pure and intense prayers. For even from that first and lowest sort, which has to do with recalling the future judgment, the one who is still subject to the punishment of terror and the fear of judgment is occasionally so struck with compunction that he is filled with no less joy of spirit from the richness of his supplication than the one who, examining the kindnesses of God and going over them in the purity of his heart, dissolves into unspeakable gladness and delight. For, according to the words of the Lord, the one who realizes that more has been forgiven him begins to love more.
I shall speak first about control of the stomach, the opposite to gluttony, and about how to fast and what and how much to eat. I shall say nothing on my own account, but only what I have received from the Holy Fathers. They have not given us only a single rule for fasting or a single standard and measure for eating, because not everyone has the same strength; age, illness or delicacy of body create differences. But they have given us all a single goal: to avoid over-eating and the filling of our bellies... A clear rule for self-control handed down by the Fathers is this: stop eating while still hungry and do not continue until you are satisfied.
How great the evil of pride is, that it deserves to have as its adversary not an angel or other virtues contrary to it but rather God Himself! For it must be noted that it is never said of those who are caught up in the other vices that the Lord resists them, or that the Lord is set against the gluttonous, or fornicators, or the angry, or the avaricious; this is true of the proud alone. For those vices only turn back upon wrongdoers or seem to be committed against those who have a part in them -- that is, against other human beings. This one, however, of its very nature touches God, and therefore it is specially worthy of having God opposed to it.
If we remember that thief who, for a single confession, was taken into Paradise, we shall realize that it was not for the merit of the life he lived that he obtained so great blessedness, but that it was his by the gift of God, Who had mercy on him. Or let us think of David, the king, whose two such grievous and awful crimes were wiped away by one word of penitence. Neither here do we see that the merit of what he did was equal to obtaining pardon for such great offense, but the grace of God did the more abound when on the occasion of true penitence He did away with all that weight of sin for one single word of genuine confession. Again, when we consider the beginnings of man's calling and salvation, which, as the Apostle tells us, is not of ourselves or of our words, but we are saved by the gift and grace of God, we shall be able clearly to perceive how the end of perfection is not 'of him that willeth, nor of him that runneth, but of God Who showeth mercy,' Who makes us victors over our vices, although we have no merit at all of life or labors to weigh against them, nor does the effort of our will avail for us to reach the steep summit of righteousness, or to subdue the flesh which we are bound to use... For the outcome of all good flows from His grace, Who hath bestowed so great an eternity of bliss and such immeasurable glory, with manifold generosity, upon the weak will and the short life-work of man.
The abstinent withdraws from gluttony, the uncovetous from covetousness, the silent from wordiness, the pure from attachment to sensory pleasures, the chaste from fornication, he who is content with what he has from love of money, the meek from agitation (anger), the humble from vanity, the obedient from objection, he who is honest with himself from hypocrisy; equally, he who prays withdraws from despair, the willing pauper from acquisitiveness, he who professes his faith from denying it, the martyr from idolatry – so you see that each virtue, performed even unto death, is nothing but withdrawal from sin; and withdrawal from sin is a natural action, not an action which could be rewarded by the kingdom.
Of the Only Case in Which Anger is Good... But we have a use for anger most properly planted within us, and for this use alone it is profitable and healthful for us to entertain it, namely, when we burn with wrathful indignation against the lustful motions of our own hearts, and are enraged to find that those things which we should be ashamed to do or to speak of before men have found admittance into the secret places of our minds. We may then well dread and fear exceedingly the presence of the Angels and the Omnipresence of God Himself, and His all-seeing Eye from which no secrets of our hearts can lie hid.
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...
In order to preserve the mind and body in a perfect condition abstinence from food is not alone sufficient: unless the other virtues of the mind as well are joined to it. And so humility must first be learned by the virtue of obedience, and grinding toil and bodily exhaustion. The madness of anger should be controlled; the downcast look of dejection be overcome; vainglory should be despised, the disdainfulness of pride trampled under foot, and the shifting and wandering thoughts of the mind restrained by continual recollection of God. And the slippery wanderings of our heart should be brought back again to the contemplation of God as often as our crafty enemy, in his endeavour to lead away the mind a captive from this consideration, creeps into the innermost recesses of the heart.
Blessed are the pure in heart, for they shall see God. Everything we do, our every objective, must be undertaken for the sake of this purity of heart. This is why we take on loneliness, fasting, vigils, work, nakedness. For this we must practice the reading of the Scripture, together with all the other virtuous activities, and we do so to trap and to hold our hearts free of the harm of every dangerous passion and in order to rise step by step to the high point of love.
If the Apostles and Martyrs, while still in the body, can pray for others, at a time when they must still be anxious for themselves, how much more after their crowns, victories, and triumphs are won! One man, Moses, obtains from God pardon for six hundred thousand men in arms; and Stephen, the imitator of the Lord, and the first martyr in Christ, begs forgiveness for his persecutors; and shall their power be less after having begun to be with Christ? The Apostle Paul declares that two hundred three score and sixteen souls, sailing with him, were freely given him; and, after he is dissolved and has begun to be with Christ, shall he close his lips, and not be able to utter a word in behalf of those who throughout the whole world believed at his preaching of the Gospel? And shall the living dog Vigilantius be better than that dead lion?