St. Peter of Damascus teaches, 'When joy comes, represent sorrow to yourself; and when you are encompassed by sorrow, try to awaken joy.' Thus you will be safeguarded both against deception and against despair.
Be slow and dull to idle talk, but knowing and wise in hearkening to the saving words of the Holy Scriptures. Let the hearing of worldly tales be to you as a bitter taste in your mouth, but the discourse of holy men as a honeycomb (Prov. 16.24). Be eager to imitate men of disciplined habits and do not wait to be taught each thing. Strive to attain to the greater virtues, but do not neglect the lesser ones. Do not make light of a fall even if it be the most venial of faults; rather, be quick to repair it by repentance, although many others may commit a large number of faults, slight and grievous, and remain unrepentant. Judge not the sins of others, for they have a just Judge ‘Who will render every man according to his works’ (Rom. 2.6); but be master of what is your own and lighten your own burden insofar as you have the power, for he who increases his own burden will also carry it. In repentance is salvation, but folly is the death of repentance.
Let us go forward with the heart completely attentive and the soul fully conscious. For if attentiveness and prayer are daily joined together, they become like Elias' fire-bearing chariot, raising us to heaven. What do I mean? A spiritual heaven, with sun, moon and stars, is formed in the blessed heart of one who has reach a state of watchfulness, or who strives to attain it.
A thick rope is composed of thin strands of hemp. One thin strand cannot hold you bound nor strangle you, for you will easily, with the lightest touch, break it and free yourself. But if a thick rope binds you, you will stay bound, and it will strangle you. You cannot easily break it and free yourself of it. As a thick rope is made from thin, weak strands, so men's passions are made up of smaller initial sins. The small, initial sins a man can still break and free himself of. But sin on sin, repeated, the weave becomes thicker and thicker until it becomes a passion, which masters a man as only it can do. You can neither cut it out easily nor cast it away from you nor be divorced from it. Oh, when will men guard themselves from these first sins? Then they would not have so much difficulty in freeing themselves from the passions.
'And forgive us our debts as we also forgive our debtors.' For we have many sins. For we offend both in word and in thought, and very many things we do worthy of condemnation; and 'if we say that we have no sin' (I Jn. 1:8), we lie, as John says...The offenses committed against us are slight and trivial, and easily settled; but those which we have committed against God are great, and need such mercy as His only is. Take heed, therefore, lest for the slight and trivial sins against you, you shut out for yourself forgiveness from God for your very grievous sins.
It is impossible for the mind to escape disturbing thoughts, but it is possible, for any who take sufficient care, either to admit them or reject them.
It is, indeed, impossible for the mind not to be troubled by thoughts, but accepting them or rejecting them is possible for everyone who makes an effort...therefore we practice the frequent reading of Scripture, so that we may be open to a spiritual point of view. For this reason we frequently chant the psalms, so that we may continually grow in compunction. For this reason we are diligent in vigils, fasting, and praying, so that the mind which has been stretched to its limits may not taste earthly things but contemplate heavenly ones. When these things cease because negligence has crept in again, then, it is inevitable that the mind, by the accumulated filth of the vices, will soon turn in a carnal direction and fall.
According to the teaching of the Fathers, any impression which, touching the heart, fills it with a great irritation, must come from the region of passions. Therefore impulses which spring from the heart should not be followed at once, but only after careful examination and fervent prayer. God preserve us from a blind heart! It is well known that passions do blind the heart and screen the shining sun of the mind that we should all strive to gaze at.
A life of spiritual endeavor is the mother of sanctity; from it is born the first experience of perception of the mysteries of Christ--which is called the first stage of spiritual knowledge.
Let us, therefore, not flinch from fighting the good fight on behalf of the truth, nor, in despair, fling away from labors we have already achieved. For the strength of the soul is not shown by one brave deed, nor yet by effort only for a short time; but He Who tests our hearts wishes us to win crowns of righteousness after long and protracted trial. Only let our spirit be kept unbroken, the firmness of our faith in Christ be maintained unshaken, and ere long our Champion will appear; He will come and will not tarry. Expect tribulation after tribulation, hope upon hope; yet a little while; yet a little while. Thus the Holy Ghost knows how to comfort His nurslings by a promise of the future. After tribulations comes hope, and what we are hoping for is not far off, for let a man name the whole of human life, it is but a tiny interval compared with the endless age which is laid up in our hopes.