A MAN is raised up from the earth by two wings -- simplicity and purity. There must be simplicity in his intention and purity in his desires. Simplicity leads to God, purity embraces and enjoys Him.
If your heart is free from ill-ordered affection, 
no
good deed will be difficult for you. If you aim at and seek after nothing but
the pleasure of God and the welfare of your neighbor, you will enjoy freedom
within.
If your heart were right, then every created thing would be a mirror of life for you and a book of holy teaching, for there is no creature so small and worthless that it does not show forth the goodness of God. If inwardly you were good and pure, you would see all things clearly and understand them rightly, for a pure heart penetrates to heaven and hell, and as a man is within, so he judges what is without. If there be joy in the world, the pure of heart certainly possess it; and if there be anguish and affliction anywhere, an evil conscience knows it too well.
As iron cast into fire loses its rust and becomes glowing white, so he who turns completely to God is stripped of his sluggishness and changed into a new man. When a man begins to grow lax, he fears a little toil and welcomes external comfort, but when he begins perfectly to conquer himself and to walk bravely in the ways of God, then he thinks those things less difficult which he thought so hard before.
WE MUST not rely too much upon ourselves, for grace and understanding are often lacking in us. We have but little inborn light, and this we quickly lose through negligence. Often we are not aware that we are so blind in heart. Meanwhile we do wrong, and then do worse in excusing it. At times we are moved by passion, and we think it zeal. We take others to task for small mistakes, and overlook greater ones in ourselves. We are quick enough to feel and brood over the things we suffer from others, but we think nothing of how much others suffer from us. If a man would weigh his own deeds fully and rightly, he would find little cause to pass severe judgment on others.
The interior man puts the care of himself before all other concerns, and he who attends to himself carefully does not find it hard to hold his tongue about others. You will never be devout of heart unless you are thus silent about the affairs of others and pay particular attention to yourself. If you attend wholly to God and yourself, you will be little disturbed by what you see about you.
Where are your thoughts when they are not upon yourself? And
after attending to various things, what have you gained if you have neglected
self? If you wish to have true peace of mind and 
unity
of purpose, you must cast all else aside and keep only yourself before your
eyes.
You will make great progress if you keep yourself free from all temporal cares, for to value anything that is temporal is a great mistake. Consider nothing great, nothing high, nothing pleasing, nothing acceptable, except God Himself or that which is of God. Consider the consolations of creatures as vanity, for the soul that loves God scorns all things that are inferior to Him. God alone, the eternal and infinite, satisfies all, bringing comfort to the soul and true joy to the body.