What is interesting about the English word fast is that it means “to move quickly” and “to abstain from food,” but we also use it in phrases like “hold fast,” which means “to hold firmly.” How did we get these varied meanings from this one word? The answer is found in the origin of the word. Fast comes from the Old English fæst, which means firm, fixed, secure, or constant.
When we see how these words are all related in their core idea, it becomes clear that as fast evolved into Modern English, it took on these separate nuances. Secure and constant developed into the notion of quickness; firm and secure inform the idea of holding fast; and fixed and constant give us the concept of fasting as a determined posture of not eating food.
But when we speak of fasting as a religious endeavor — withholding or abstaining from taking food — the origin of this cross-cultural and cross-religious practice dates back millennia, typically carrying the notion of purification, humility, and drawing near to the divine, the idea being that the physical must be set aside to achieve the spiritual.
In the Christian tradition, its roots are found in the Hebrew Old Testament, where in ancient Israel it was connected with repentance, mourning, prayer, and reliance upon God. We see fasting practices throughout the Bible — from Moses, who fasted forty days on Mount Sinai before receiving the Law (Exodus 34:28), to David, who fasted in grief and repentance (2 Samuel 12:16), to the prophet Daniel, who fasted and prayed for wisdom and mercy (Daniel 9:3), as well as in the call from Queen Esther, who called upon her people to fast for three days before she approached the king (Esther 4:16).
In the New Testament, fasting continues as a discipline to help us grow spiritually, as it calls us to find our dependence upon God — to put our love for the Lord over our desires for satisfaction. Jesus Himself fasted for forty days in the wilderness, and when the devil tempted Him to turn stones into bread to relieve His hunger, Jesus refused and quoted Scripture, saying:
“It is written, ‘Man shall not live by bread alone, but by every word that comes from the mouth of God.’” — Matthew 4:4; cf. Deuteronomy 8:3
Fasting, then, is a way to declare to the Lord our reliance upon Him. It is a practice of putting God before our desires — namely, our desire for food. As the hunger pangs come, they serve as reminders to turn our focus to God and to direct our energy into prayer.
Fasting is a powerful discipline that, when done rightly, can help us grow spiritually and deepen our faith. It is not simply about deprivation, but rather about devotion — about training our spirits to hunger for righteousness (Matthew 5:6).
In college, my Spiritual Formation professor also warned against fasting as a means to simply lose weight, and Jesus also warns against fasting for the wrong reasons, such as using it to display our righteousness before others. He said:
“When you fast, do not look gloomy like the hypocrites, for they disfigure their faces that their fasting may be seen by others. Truly, I say to you, they have received their reward. But when you fast, anoint your head and wash your face, that your fasting may not be seen by others but by your Father who is in secret. And your Father who sees in secret will reward you.” — Matthew 6:16–18
All of Isaiah 58 is about true and false fasting, where we see that God calls us to fast in order to grow spiritually as we reflect God’s good will in this world and find our delight in the Lord. Again, this spiritual discipline only helps us grow spiritually when done for spiritually righteous reasons. Thus, fasting is typically a private practice — a personal act of humility and devotion before God. It is a way of living out the truth that the Bible reminds us of: that “man does not live by bread alone” (Deuteronomy 8:3; Matthew 4:4).
Fasting does not have a set prescribed length of time. In the Bible, we see fasts lasting from one day (Judges 20:26; 1 Samuel 7:6) to three days (Esther 4:16) to forty days (Exodus 34:28; Matthew 4:2). As a spiritual discipline, there is no single method. Many people choose to fast for a day or even skip a single meal. The point is less about how we fast and more about why — it’s an act of faith meant to draw us closer to God.
You might choose a three-month period in which you fast only one day a week, or a week-long fast where every day you skip a particular meal, like lunch.
While fasting traditionally means abstaining from food, modern practices also include other kinds of fasts — such as fasting from technology, entertainment, or particular types of food, like meat or sugar (see Daniel 10:2–3). But the practice we see most clearly in Scripture is to abstain from food completely.
Again, the notion here is about setting aside our desires in order to deepen our reliance upon God as we grow closer to Him in trust, love, and joy. While this is a spiritual practice, it does have physical implications and so for those with health concerns, it’s always good to consult with your doctor before you begin this discipline.
So as the Lord leads you, may you prayerfully practice the spiritual discipline of fasting in order that you may continue to grow into the person God is calling you to become as you deepen your faith in the God of your salvation and satisfaction.
