1. The What and Why of Mortification by Fr. John Hardon. Short, sound, and basic. A great piece for anyone who feels called to enter the life of mortification, but is unsure what exactly to do. An example:
We can practice mortification by giving up some delicacy in food or drink or some pleasure that we could legitimately have. But we also practice mortification every time we patiently accept whatever trial or pain He sends us and every time we faithfully carry out whatever His mysterious providence commands of us. It is this second kind of mortification that Jesus had in mind when He told us that “anyone who loses his life for My sake, will find it” (Matthew 16:25).
2. Seeking Sanctification Through the Practice of Mortification by Fr. Roger J. Scheckel. A longer and far more detailed essay on the what and why of mortification. It seeks to show that mortificaiton is necessary if you want to be a saint. Necessary, yet not exactly fun, reading. An example:
The Christian must continually seek to crucify and put to death that dimension of our self that remains under the influence of the fallen state of the First Adam into which we are conceived and born. After our baptism, the imputed sin of our First Parents is washed from our life; however, a residue or stain of the Original Sin remains with us, what is known as concupiscence. The effects of this residue or stain are experienced primarily in our will, tending in the direction of a love of self rather than a love of God. This is what is meant by a “disordered will.” This disorder can be expressed through our external senses as well as the operations of our soul, e.g., the imagination, memory and intellect. Mortification seeks to address these manifestations of the “disordered will.”
Sacred Tradition expressed through the lives of the saints provides innumerable accounts of the necessity and importance of the practice of mortification. I would direct you to the lives of the saints listed below, although there are many more that could be included as well: Ss. Jerome, Francis of Assisi, Thomas More, Ignatius of Loyola, Catherine of Sienna, Teresa of Avila, John Mary Vianney, Therese of the Child Jesus, Padre Pio of Pietrelcina, Jose Maria Escriva, and also Blesseds Junipero Serra, Matt Talbot, and Mother Teresa.
“It is true, whoever said it, that the soul and the body are two enemies that cannot be separated, and two friends that cannot get along.” The Way #195 St. Josemaria Escriva