"Once we have detached ourselves from the world, and from our kinsfolk, and are cloistered here, in the conditions already described, it must look as if we have done everything and there is nothing left with which we have to contend. But, oh, my sisters, do not feel secure and fall asleep, or you will be like a man who goes to bed quite peacefully, after bolting all his doors for fear of thieves, when the thieves are already in the house. And you know there is no worse thief than one who lives in the house. We ourselves are always the same; unless we take great care and each of us looks well to it that she renounces her self-will, which is the most important business of all, there will be many things to deprive us of the holy freedom of spirit which our souls seek in order to soar to their Maker unburdened by the leaden weight of the earth.
It will be a great help towards this if we keep constantly in our thoughts the vanity of all things and the rapidity with which they pass away, so that we may withdraw our affections from things which are so trivial and fix them upon what will never come to an end. This may seem a poor kind of help but it will have the effect of greatly fortifying the soul. With regard to small things, we must be very careful, as soon as we begin to grow fond of them, to withdraw our thoughts from them and turn them to God. His Majesty will help us to do this. He has granted us the great favor of providing that, in this house, most of it is done already; but it remains for us to become detached from our own selves and it is a hard thing to withdraw from ourselves and oppose ourselves, because we are very close to ourselves and love ourselves very dearly.
The first thing, then, that we have to do, and that at once, is to rid ourselves of love for this body of ours -- and some of us pamper our natures so much that this will cause us no little labor, while others are so concerned about their health that the trouble these things give us (this is especially so of poor nuns, but it applies to others as well) is amazing. Some of us, however, seem to think that we embraced the religious life for no other reason than to keep ourselves alive and each nun does all she can to that end. In this house, as a matter of fact, there is very little chance for us to act on such a principle, but I should be sorry if we even wanted to. Resolve, sisters, that it is to die for Christ, and not to practice self-indulgence for Christ. From THE WAY OF PERFECTION BY ST. TERESA OF AVILA