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.
We must always pray to the Lord to tell us what to do, and the Lord will not let us go astray. Adam was not wise enough to ask the Lord about the fruit which Eve gave him, and so he lost paradise.
The heavenly is experienced through the Holy Spirit, and the earthly through the mind: whoever wants to experience God with his mind through learning is in vainglory, for God can only be experienced through the Holy Spirit.
I think it best that a man should have a little bit of all the virtues. Therefore, get up early every day and acquire the beginning of every virtue and every commandment of God. Use great patience, with fear and long-suffering, in the love of God, with all the fervor of your soul and body. Exercise great humility, bear with interior distress; be vigilant and pray often with reverence and groaning, with purity of speech and control of your eyes. When you are despised do not get angry; be at peace, and do not render evil for evil. Do not pay attention to the faults of others, and do not try to compare yourself with others, knowing you are less than every created thing. Renounce everything material and that which is of the flesh. Live by the cross, in warfare, in poverty of spirit, in voluntary spiritual asceticism, in fasting, penitence and tears, in discernment, in purity of soul, taking hold of that which is good. Do your work in peace. Persevere in keeping vigil, in hunger and thirst, in cold and nakedness, and in sufferings. Shut yourself in a tomb as though you were already dead, so that at all times you will think death is near.
O man, learn the humility of Christ and the Lord will give you to taste of the sweetness of prayer. And if you would pray cleanly, be humble and temperate, confess yourself thoroughly, and prayer will feel at home in you. Be obedient, submit with a good conscience to those in authority; be content with all things, and your mind will be cleansed of vain thoughts. Remember that the Lord sees you, and be fearful lest you anywise offend your brother, whom neither dispraise nor grieve, even by a look, and the Holy Spirit will love you and will Himself be your help in all things.
Behold, this is the true and the Christian humility. In this you will be able to achieve victory over every vice, by attributing to God rather than to yourself the fact that you have won.