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.
Whether you pray with brethren or alone, try to pray not simply as a routine, but with conscious awareness of your prayer. Conscious awareness of prayer is concentration accompanied by reverence, compunction and distress of soul as it confesses its sin with inward sorrow.
Join to every breath a sober invocation of the name of Jesus and the thought of death with humility. Both these practices bring great profit to the soul.
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.
Praise God continually with spiritual hymns and always remain in meditation and in this way you will be able to bear the burden of the temptations that come upon you. A traveler who is carrying a heavy load pauses from time to time and draws in deep breaths; it makes the journey easier and the burden lighter.
Whenever we enter the church and draw near to the heavenly mysteries, we ought to approach with all humility and fear, both because of the presence of the angelic powers and out of the reverence due to the sacred oblation; for as the Angels are said to have stood by the Lord's body when it lay in the tomb, so we must believe that they are present in the celebration of the Mysteries of His most sacred Body at the time of consecration.
The enemy is within ourselves. An invisible war is taking place within us. If interior evil is defeated, then the external, weaker, foe will surrender.
Let not us who would be Christians expect anything else than to be crucified...for to be Christian is to be crucified in this time and in any time since Christ came for the first time. His life is the example and warning to us all. We must be crucified personally, mystically; for through crucifixion is the only path to resurrection, if we would rise with Christ, we must be humbled with him even to the ultimate humiliation, being devoured and spit forth by the uncomprehending world...we must be crucified outwardly in the eyes of the world, for Christ’s kingdom is not of this world and the world cannot bear it, even a single representative, even for the single moment. The world can only accept Antichrist now or at any time.
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.
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.