Thomas a Kempis, The Imitation of Christ 3.53

That the Grace of God does not join itself to those who mind earthly things 

1. “My Son, precious is My grace, it suffers not itself to be joined with outward things, nor with earthly consolations. Therefore you ought to cast away all things which hinder grace, if you long to receive the inpouring thereof. Seek a secret place for yourself, love to dwell alone with yourself, desire the conversation of no one; but rather pour out your devout prayer to God, that you may possess a contrite mind and a pure conscience. Count the whole world as nought; seek to be alone with God before all outward things. For you cannot be alone with Me, and at the same time be delighted with transitory things. You ought to be separated from your acquaintances and dear friends, and keep your mind free from all worldly comfort. So the blessed Apostle Peter beseeches, that Christ’s faithful ones bear themselves in this world as strangers and pilgrims. 

2. “Oh how great a confidence shall there be to the dying man whom no affection to anything detains in the world? But to have a heart so separated from all things, a sickly soul does not yet comprehend, nor does the carnal man know the liberty of the spiritual man. But if indeed he desires to be spiritually minded, he must renounce both those who are far off, and those who are near, and to beware of no man more than himself. If you perfectly conquer yourself, very easily shall you subdue all things besides. Perfect victory is the triumph over oneself. For whoso keeps himself in subjection, in such manner that the sensual affections obey the reason, and the reason in all things obeys Me, he truly is conqueror of himself, and lord of the world. 

3. “If you desire to climb to this height, you ought to start bravely, and to lay the axe to the root, to the end that you may pull up and destroy the hidden inordinate inclination towards yourself, and towards all selfish and earthly good. From this sin, that a man loves himself too inordinately, almost everything hangs which needs to be utterly overcome: when that evil is conquered and put under foot, there shall be great peace and tranquillity continually. But because few strive earnestly to die perfectly to themselves, and do not heartily go forth from themselves, therefore do they remain entangled in themselves, and cannot be raised in spirit above themselves. But he who desires to walk at liberty with Me, must of necessity mortify all his evil and inordinate affections, and must cling to no creature with selfish love.”