St. Augustine of Hippo Sermon 205, 1
“As we begin our annual Lenten observance with its solemn call to conversion…it is more than ever my pastoral duty to nourish your minds with the word of God when you are about to mortify your bodies by fasting. We are soon to celebrate the Passion of our crucified Lord. It is therefore in keeping with our commitment to him that we should crucify ourselves by restraining the desires of the flesh.
As St Paul says: You cannot belong to Christ Jesus unless you crucify all your self-indulgent passions and desires. Such is the Cross upon which we Christians must continually hang, since our whole lives are beset by trials and temptations. Not for us, as long as we live, to be rid of those nails we read of in the psalm: Pierce my flesh with the nails of your fear. Flesh means the desires of our lower nature; nails, the demands of God’s justice and holiness. With these the fear of the Lord pierces our flesh and fastens us to the Cross as an acceptable sacrifice to him.
In a similar passage the apostle Paul appeals to us by the mercy of God to offer our bodies as a living sacrifice, holy and acceptable to God. To hang on such a Cross brings no shame to the servants of God; it is something in which they glory, as Saint Paul does when he says: Far be it from me to glory in anything except in the Cross of our Lord Jesus Christ, through whom the world has been crucified to me, and I to the world.
This crucifixion, I repeat, is something that must continue throughout our life, not for forty days only. It is true that Moses, Elijah, and our Lord himself fasted for forty days; but in Moses, Elijah, and Christ we are meant to see the Law, the Prophets, and the Gospel, and to learn from them not to cling to this present world or imitate its ways, but to nail our unregenerate selves to the Cross. Christians must always live in this way, without any wish to come down from their Cross, otherwise they will sink beneath the world’s mire. But if we have to do so all our lives, we must make an even greater effort during these days of Lent. It is not a simple matter of living through forty days; Lent is the epitome of our whole life.”