This closing line in today’s first reading from Isaiah (58:1-9a) is predicated on performing corporal works of mercy.  All but one of the traditional corporal works of mercy are laid out in the judgment of the nations in Matthew’s Gospel (25:35-36).  But Isaiah anticipates the value of some of these good deeds here in discussing what the Lord God really desires from His followers.  The people focus on their fasting and penitential practices in their cry to Yahweh, but He only sees their worldliness and mistreatment of others.  If they have to choose, God would much prefer them to pursue

releasing those bound unjustly,
untying the thongs of the yoke;
Setting free the oppressed,
breaking every yoke;
Sharing your bread with the hungry,
sheltering the oppressed and the homeless;
Clothing the naked when you see them,
and not turning your back on your own. (vv. 6-7)

The result of doing this?

Then your light shall break forth like the dawn,
and your wound shall quickly be healed;
Your vindication shall go before you,
and the glory of the LORD shall be your rear guard. (v. 8)

The word “light” here is interesting.  Our light is Christ (see Jn 8:12, 1:9; 2 Cor 4:6; Eph 5:8-9) .  When this light “breaks forth” from us, it is effective because it is the light of Christ.  He makes our good works meritorious.  In doing works of mercy we become the face of Christ, the Face of Mercy (see Misericordiae Vultus), to others.  Others will see Jesus in us and experience Him through us.

All that said, Scripture does not oppose fasting and good works.  Jesus Himself says, “When you fast” (Mt 6:16).  This is not an optional practice.  Even in today’s Gospel passage Jesus says, “The days will come when the bridegroom is taken away from them,
and then they will fast” (Mt 9:15).  Finally, remember these words of our Lord, in some ancient manuscripts, speaking of demonic influence: “this kind does not come out except by prayer and fasting” (Mt 17:21).

So, we are to practice fasting.  Fasting as we await Christ’s return in glory.  Fasting as we work to counter the influence of the Evil One in our culture and in our world.  Fasting to learn detachment from worldly goods so that we can truly approach being “poor in spirit” (Mt 5:3).  A good practice is to make every Friday throughout the year a Lenten Friday (no meat).  Better yet is to make a “Good Friday” every week — no meat and “one full meal, as well as two smaller meals that together are not equal to a full meal” (USCCB).  It is not uncommon to extend this same practice to Wednesdays as well.

In a world that more and more is being given over to the culture of death, may we bring the light of Christ, who is the Life (Jn 14:6), through our fasting, penance, and works of mercy.