Thomas à Kempis on The Imitation of Christ...

'He who follows Me shall not walk in darkness,' says Our Lord.

In these words Christ counsels us to follow His life and way if we desire true enlightenment and freedom from all blindness of heart. Let the life of Jesus Christ, then, be our first consideration.

The teaching of Jesus far transcends all the teachings of the Saints, and whosoever has His spirit will discover concealed in it heavenly manna. But many people, although they often hear the Gospel, feel little desire to follow it, because they lack the spirit of Christ. Whoever desires to understand and take delight in the words of Christ must strive to conform his whole life to him.

Of what use is it to discourse learnedly on the Trinity, if you lack humility and therefore displease the Trinity? Lofty words do not make a man just or holy; but a good life makes him dear to God. I would far rather feel contrition than be able to define it. If you knew the whole Bible by heart, and all the teachings of the philosophers, how would this help you without the grace and love of God? 'Vanities of vanities, and all is vanity,' except to love God and serve him alone. And this is supreme wisdom -- to despise the world, and draw daily nearer the kingdom of heaven. 

It is vanity to solicit honours, or to raise oneself to high station. It is vanity to be a slave to bodily desires, and to crave for things which bring certain retribution. It is vanity to wish for long life, if you care little for a good life. It is vanity to give thought only to this present life, and to care nothing for the life to come. It is vanity to love things that so swiftly pass away, and not to hasten onwards to that place where everlasting joy abides.

Keep constantly in mind the saying, 'The eye is not satisfied with seeing, not the ear filled with hearing.' Strive to withdraw your heart from the love of visible things, and direct your affections to things invisible. For those who follow only their natural inclinations defile their conscience, and lose the grace of God.