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.
Remember that a good action is always either preceded or followed by temptations. God permits this so that the virtue, exercised in that particular action, may be confirmed, consolidated, steeled.
Temptations are sent for improvement when God delivers his righteous ones to various temptations, humiliating them for some slight and unimportant offense, or to increase their purity, in order that every uncleanliness of thought, or... dross which He sees they have harbored in secret, may be burnt away in this present life, and that so He may bring them, as it were pure gold, to the future judgment...
Waves of temptation of every sort were aimed at the righteous ones, but they did not grow faint. Glory did not make them haughty, nor did abusive treatment cause them to be despondent. They were always the same; never did the fragrance of their virtues falter.
Trials are of two kinds. Either affliction will test our souls as gold is tried in a furnace, and make trial of us through patience, or the very prosperity of our lives will oftentimes, for many, be itself an occasion of trial and temptation. For it is equally difficult to keep the soul upright and undefeated in the midst of afflictions, as to keep oneself from insolence and pride in prosperity.
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.
Many are the obstacles that stand in the way of pleasing God; for not merely poverty and obscurity but also riches and honor are trials for the soul. Indeed, to some extent even the solace and ease which grace bestows on the soul can easily become a temptation and a hindrance if the soul is not properly conscious of these effects of grace and does not enjoy them with great circumspection and understanding: for the spirit of evil tries to persuade the soul to relax now it possesses grace, and so contrives to implant in it sluggishness and apathy.
All the pleasers of God are like the angels in their love and devotion. They, just as the angels, waged war against the dark forces, and became strengthened in love of God. All of the prophets of the Old Testament lived in such a struggle. Godlessness prevailed, the Law of God was forgotten. The world persecuted them because they interfered with its sinful life. They hid in the 'depths of the earth.' The world hated them. The prophet Isaiah was sawed in two by a wooden saw, the prophet Jeremiah was trampled in a swamp. And in such surroundings they stood fast in faith and devotion. All righteous ones were sorrowful in the world because they were strangers to the sinful world. All of the apostles suffered in one way or another. Righteous men left for the desert. What made them saints? Suffering? Not suffering alone makes saints, but striving towards God, love of God, and the labor of overcoming obstacles to holiness, which is the fruit of man's labor and the gift of the Holy Spirit.
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.
Do not oppose the thoughts, which the enemy sows in you, but rather cut off all converse with them by prayer to God. We have not always strength enough so to oppose hostile thoughts as to stop them; on the contrary, in such attempts they frequently inflict us with a wound that is long in healing.
Train yourself to cut off an intrusive thought immediately… Be at pains over this, so that you acquire the habit. The soul is a creature of habit: according to the habit you have acquired, so will you act all the rest of your life.
The temptation comes in accordance with one’s stature. And you must endure in order to emerge victorious. Christ, Who sets the contest, allows temptations for this reason: so that we may gain victories against the enemy, be purged from passions, and be perfected.
If we desire to acquire faith the foundation of all blessings, the door to God's mysteries, unflagging defeat of our enemies, the most necessary of all the virtues, the wings of prayer and the dwelling of God within the soul--we must endure every trial imposed by our enemies and by our many and various thoughts... if we forcibly triumph over the trials and temptations that befall us, it will not be we who are victorious, but Christ, Who is present in us through faith.
For by prayer we obtain the divine favor, by fasting we extinguish the concupiscences of the flesh, by almsgiving sins are redeemed (Dan. iv. 24); and by all three together, the image of God is renewed in us, provided that we are ever ready in His praise, eager without ceasing for our own purification, and disposed at all times to assist our neighbor.