The practice of Humility - 29

No matter how high the degree of grace and virtue you have achieved, no matter how great the gift of prayer God has given you, even if you have lived one thousand years in innocence and with fervor and devotion, you must always walk vigilant and distrust yourself, especially in the matter of chastity.  Remember that you carry within yourself concupiscence, an inextinguishable source of sin; think that you are all weakness, inconstancy, infidelity.

Be always on guard against yourself; close your eyes to avoid seeing or hearing what could stain your soul; always run away from dangerous occasions; abstain from useless conversation with the opposite sex, and carry on the necessary dealings with the most scrupulous modesty and prudence.

Finally, since without the grace of God you can do nothing, continually ask God to have mercy on you, that you do not remain on your own for a moment.

J. Pecci (later Pope Leo XIII)