Why Do We Fast In Lent?

What an Ancient Lenten Hymn Can Teach Us

Each year around Lent, kids ask the same question: Why do we fast?

We could try to answer with a twenty-minute explanation about Jesus in the wilderness, the historical practice of the Church, and the Church’s spiritual discipline. That lecture would be accurate, but it would also be a lot for a child who just wants to know why cookies have disappeared for forty days.

Or we could sing a two-minute hymn.

The Glory of These Forty Days is the English translation¹ of an ancient hymn written by St. Gregory the Great:² Clarum decus jejunii. In four verses,³ it explains why Christians fast, where the practice comes from, and why it’s good for us.

It’s not just a beautiful song; it’s also a work of theology.

We Fast Because Christ First Fasted

The glory of these forty days
we celebrate with songs of praise,
for Christ, by whom all things were made,
himself has fasted and has prayed.

The most basic reason we fast in Lent is to imitate Christ. Before beginning his public ministry, Jesus withdrew into the wilderness and fasted for forty days, and Lent’s forty days echo that period. By fasting, we intentionally share in Christ’s discipline and preparation.

Scripture repeatedly⁴ emphasizes the importance of following Jesus’ example. During Lent, we follow Christ into the wilderness with fasting and prayer.

We Fast as Part of a Long Biblical Tradition

Alone and fasting Moses saw
the loving God who gave the law.
And to Elijah, fasting, came
the steed and chariots of flame.

So Daniel trained his mystic sight,
delivered from the lion’s might.
And John, the Savior’s friend, became
the herald of Messiah’s name.

But Jesus’ fasting did not come out of nowhere. Throughout the Old Testament and into the New Testament, including in the ministry of John the Baptist, fasting was a common spiritual discipline of preparation. Fasting during Lent places us in continuity with that tradition.

We Fast to Train Our Desires

Then grant, O God, that we may, too,
return in fast and prayer to you.
Our spirits strengthen with your grace,
and give us joy to see your face.

And fasting isn’t only symbolic. It cultivates self-control, redirecting our desires toward God. By voluntarily giving up something pleasurable, we practice saying no to our desires so that we can say yes to God more readily.

A Simple Summary

So we fast during Lent for three reasons:

1. To imitate Christ

2. To continue the tradition

3. To train self-control

1. Translated by Anglican minister Maurice F. Bell in 1906.

2. He is also known for the style of chant that bears his name.

3. A fifth verse includes a traditional invocation of the Trinity.

4. See 1 Corinthians 11:1, Ephesians 5:1, 1 John 2:6, Philippians 2:5, and Romans 13:14.