Attacks of the devil…

The crown of every good endeavor and the highest of achievements is diligence in prayer. Through it God guiding us and lending a helping hand, we come to acquire the other virtues . . . as the work of prayer is greater than other work, so it demands greater effort and attention from the person ardently devoted to it, lest without him being aware the devil deprives him of it. The greater the good a person has in his care, the greater the attacks the devil launches on him; hence he must keep strict watch, so that fruits of love and humility, simplicity and goodness – and, along with them, fruits of discrimination – may grow daily from the constancy of his prayer. These will make evident his progress and increase in holiness, thus encouraging others to make similar efforts.
–Saint Symeon Metaphrastis (Tenth Century)

If you fall, rise up…

should we fall, we should not despair and so estrange ourselves from the Lord’s love. For if He so chooses, He can deal mercifully with our weakness. Only we should not cut ourselves off from Him or feel oppressed when constrained by His commandments, nor should we lose heart when we fall short of our goal…let us always be ready to make a new start. If you fall, rise up. If you fall again, rise up again. Only do not abandon your Physician, lest you be condemned as worse than a suicide because of your despair. Wait on Him, and He will be merciful, either reforming you, or sending you trials, or through some other provision of which you are ignorant.
–Saint Peter of Damascus (d. 750)

Do not despair…

Even if you are not what you should be, you should not despair. It is bad enough that you have sinned; why in addition do you wrong God by regarding him in your ignorance as powerless? Is he, who for your sake created the great universe that you behold, incapable of saving your soul? And if you say that this fact, as well as his incarnation, only makes your condemnation worse, then repent; and he will receive your repentance, as he accepted that of the prodigal son (Luke 15:20) and the prostitute (Luke 7:37-50). But if repentance is too much for you, and you sin out of habit even when you do not want to, show humility like the publican (Luke 18:13): this is enough to ensure your salvation. For he who sins without repenting, yet does not despair, must of necessity regard himself as the lowest of creatures, and will not dare to judge or censure anyone. Rather, he will marvel at God’s compassion.
–Saint Peter of Damascus (d. 750)

Overcome vice with virtues…

Gluttony should be destroyed by self-control; unchastity by desire for God and longing for the blessings held in store; avarice by compassion for the poor; anger by goodwill and love for all men; worldly dejection by spiritual joy; listlessness by patience, perseverance and offering thanks to God; self-esteem by doing good in secret and by praying constantly with a contrite heart; and pride by not judging or despising anyone in the manner of the boastful Pharisee (cf. Lk. 18:11-12), and by considering oneself the least of all men.
–Saint John of Damascus (c. 676-750)