To free yourself from the harm the world can do you, you should practice three precautions.
The first precaution
The first is that you should have an equal love for and an equal forgetfulness of all persons, whether relatives or not, and withdraw your heart from relatives as much as from others, and in some ways even more for fear that flesh and blood might be quickened by the natural love that is ever alive among kin, and must always be mortified for the sake of spiritual perfection.
Regard all as strangers, and you will fulfill your duty toward them better than by giving them the affection you owe God. Do not love one person more than another, for you will err; the person who loves God more is the one more worthy of love, and you do not know who this is. But forgetting everyone alike, as is necessary for holy recollection, you will free yourself from this error of loving one person more or less than another.
the person who loves God more is the one more worthy of love, and you do not know who this is
Do not think about others, neither good things nor bad. Flee them inasmuch as possible. And if you do not observe this practice, you will not know how to be a religious, nor will you be able to reach holy recollection or deliver yourself from imperfections. And if you should wish to allow yourself some freedom in this matter, the devil will deceive you in one way or another, or you will deceive yourself under some guise of good or evil.
In doing what we said, you will have security, for in no other way will you be capable of freeing yourself from the imperfections and harm derived from creatures.
Saint John of the Cross
The Precautions (excerpt)
At age 20, Juan de Yepes y Alvarez entered the Carmelite Order, being clothed with the habit on February 24, 1563, and taking the name Juan de Santo Matia (John of Saint Matthias). Pursuing theological studies in Salamanca, he was ordained in 1567, and said his first Mass in Medina del Campo. During that trip, he first met Teresa of Avila, and she encouraged him to promote her reform among the men’s Order. In November, 1568, John and three other friars took up the observance of the primitive Carmelite Rule in a farmhouse near Duruelo. At that time, he changed his name in religion to Juan de la Cruz (John of the Cross). [Source: Manuel Diego, O.C.D.]
The Precautions The Collected Works of Saint John of the Cross, Revised Edition Translated by Kieran Kavanaugh, O.C.D. and Otilio Rodriguez, O.C.D. With Revisions and Introductions by Kieran Kavanaugh, O.C.D. ICS Publications Copyright © 1976 by Washington Province of Discalced Carmelite Friars, Inc.