When the enemy tempts you with thoughts of faithlessness, with all your heart say, I believe completely whatever the Church believes, whatever Christ says in the Holy Gospels, whatever the Holy Apostles and the Holy Fathers said. 'I don't, however, believe you, devil, for you are a liar and a thief.'
The evil one cannot comprehend the joy we receive from the spiritual life; for this reason he is jealous of us, he envies us and sets traps for us, and we become grieved and fall. We must struggle, because without struggles we do not obtain virtues.
Most men not only bear Satan's burden willingly in their hearts, but they become so accustomed to it that they often do not feel it, and even imperceptibly increase it. Sometimes, however, the evil enemy increases his burden tenfold, and then they become terribly despondent and fainthearted, they murmur and blaspheme God's name. The usual means that men... take to drive away their anguish are... entertainments... But such means afterwards increase still more the anguish and weariness of their hearts. If, happily, they turn to God, then the burden is removed from their heart, and they clearly see that previously the heaviest burden was lying on their heart, though frequently they did not feel it.
There is nothing more efficacious against the wiles of the devil, dearly beloved, than the kindness of forgiveness, and the bountifulness in charity, by means of which sin is either avoided or overcome.
Grace comes immediately to meet some of those who strive, giving them assurance of the earnest of their inheritance, (Eph. 1:14), letting them taste the promised prizes, as if stretching out a loving hand to welcome them and anointing them for further struggles. With others, however, grace waits for the end of the struggle, and prepares for them the crown of patience as well. As one of the God-bearing Fathers says, 'some receive holy rewards before their labors, some during their labors, and some when they depart.'
When you intend to do something and see that your thought is perturbed, and if after invoking God's Name it remains perturbed even by a hair's breadth, know from this that the action you mean to commit is from the evil one and refrain from commiting it. For nothing done with perturbation is pleasing to God.
The grace of the priesthood is one thing, the grace of the great schema is another, the grace of the Mysteries is different, and the action of grace in ascesis is also different. They all spring from the same source, but each one differs from the other in eminence and glory. The grace of repentance, which acts in those who struggle, is a patristic inheritance. It is a divine transaction and exchange in which we give dust and receive heaven. We exchange matter for the Spirit. Every drop of sweat, every pain, every ascesis for God is an exchange.
Beware of the counsels of the evil one, if he should come in the guise of one professing truth to beguile you and lead you into deceit. Even if he should come to you as an angel of light, do not believe him or obey him: for he is apt to fascinate the faithful by the attractive semblance of truth.
Just as our Lord is solicitous about our salvation, so too the murderer of men, the devil, strives to lead a man into despair... Judas the betrayer was fainthearted and unskilled in battle, and so the enemy, seeing his despair, attacked him and forced him to hang himself; but Peter, a firm rock, when he fell into great sin, like one skilled in battle did not despair nor lose heart, but shed bitter tears from a burning heart, and the enemy, seeing these tears, his eyes scorched as by fire, fled far from him wailing in pain.
Wherever we are and whatever our circumstances, the enemy always tries to prevent us from actively responding to the call. Pray for help. For help that you may never fail to respond. And beware lest, having received help and having done the right deed because of it, you should grow proud and acquire the habit of condemning others, in the secret chambers of your heart. Beware! For this would make all the fruits of your good works wither.