What’s the Bible have to say about Fasting?

Fasting isn’t something that just Christians do.  Other religions do it as well, like with Muslims during the month of Ramadan. For people of other faiths, or no-faith, fasting can be seen as a strange thing to do.

Since I’ve been fasting recently, it has prompted me to research what the Bible has to say about fasting. I think it is important for us to understand, whether we choose to fast or not, so we can explain it to our children and others.

This is part 1, where I will explain what is fasting, are we required to fast, and how long should we fast.  Part 2 will be next week where I dive into the reasons why people fast.

Did you know that everyone fasts once per day? It is true. We all stop eating at night, normally after dinner, and do not eat again until the next morning. Did you know that our word Breakfast, was derived from two words “Break” and “Fast”.  Essentially when you are eating breakfast, you are breaking or ending your fast from the night before.

What Is Fasting?

Before I get too far, I should make sure we are on the same page about what fasting is.  Fasting is going a period of time without liquids and/or food. When most people fast, they are going without food and are continuing to drink liquids; water, juices and/or other liquids. However, there are some that fast from liquids; only for 1-3 days, otherwise it might be fatal.

Some fast for health reasons and other for spiritual reasons.  There are lots of health benefits to fasting, but I’m going to stick to what the Bible says about fasting; so the Spiritual side.

Fasting is putting down the desires of the flesh, to show God we are sincere about seeking His will, help or guidance. Our flesh says I want more and more food. When you fast you say to your body “NO!”, and instead of eating, you spend time seeking God through prayer and reading His word. So we are putting down the flesh and walking more in the spirit.

Are We Required To Fast?

In the Old Testament, which was the time of the Law, there were times when the Jews were commanded to fast, but we are now in New Testament times during the Church / grace age, so we are not required to fast. We are free to choice whether to fast or not.

In the Old Testament, sometimes people fasted because they wanted to, and other times because they were required to. Here are Old Testament examples when they were required to fast.

Jeremiah mentions a ‘day of fasting’, indicating that it was a day where fating was required.

So you go to the Temple on the next day of fasting, and read the messages from the Lord that I have had you write on this scroll. Read them so the people who are there from all over Judah will hear them. Jeremiah 36:6 NLT

The Jews were required to fast the 4th, 5th, 7th and 10th months before a big feast. I’m not sure for how long.

“This is what the Lord of Heaven’s Armies says: The traditional fasts and times of mourning you have kept in early summer, midsummer, autumn, and winter are now ended. They will become festivals of joy and celebration for the people of Judah. So love truth and peace. Zechariah 8:19 NLT

For 70 years while the Jews were captive in Babylon, they picked certain months to fast to plead with God for freedom.

“Say to all your people and your priests, ‘During these seventy years of exile, when you fasted and mourned in the summer and in early autumn, was it really for me that you were fasting? Zechariah 7:5 NLT

Jezebel writing for Ahab proclaimed a fast in order to get Naboth’s vineyard. Albeit that this was a evil thing she did, but it still is an example of when people were told to fast.

In her letters she commanded: “Call the citizens together for a time of fasting, and give Naboth a place of honor. 1 Kings 21:9 NLT

Jehoshaphat proclaimed a fast.

Jehoshaphat was terrified by this news and begged the Lord for guidance. He also ordered everyone in Judah to begin fasting. 2 Chronicles 20:3 NLT

Ezra proclaimed a fast.

And there by the Ahava Canal, I gave orders for all of us to fast and humble ourselves before our God. We prayed that he would give us a safe journey and protect us, our children, and our goods as we traveled. Ezra 8:31 NLT

Through the Lord, Joel told the people fast because of a Locust plague.

Announce a time of fasting; call the people together for a solemn meeting. Bring the leaders and all the people of the land into the Temple of the Lord your God, and cry out to him there. Joel 1:14 NLT

The people of Niviva proclaimed a fast, after Jonah preached and they turned from their wicked ways.

The people of Nineveh believed God’s message, and from the greatest to the least, they declared a fast and put on burlap to show their sorrow. Jonah 3:5 NLT

In the past, American leaders proclaimed days of prayer and fasting. It was more a suggestion, but most Christians did it. In today’s politically correct environment, I doubt that would happen again anytime soon.

Prayer and fasting go hand and hand. When fasting, the time not spent eating should be spent in prayer and reading God’s word.

So I turned to the Lord God and pleaded with him in prayer and fasting. I also wore rough burlap and sprinkled myself with ashes. Daniel 9:3 NLT

When I heard this, I sat down and wept. In fact, for days I mourned, fasted, and prayed to the God of heaven. Nehemiah 1:4 NLT

How Long Should We Fast?

There is no set time period for how long to fast. You can decide how long you want to fast and when you want to do it. Below are some examples in Scripture of how long people fasted. They range from 1 night to 40 days.

King Darius fasted from before dinner to next morning, so a night fast.

Then the king returned to his palace and spent the night fasting. He refused his usual entertainment and couldn’t sleep at all that night. Daniel 6:18 NLT

Esther and all Jews fasted for 3 days.

“Go and gather together all the Jews of Susa and fast for me. Do not eat or drink for three days, night or day. My maids and I will do the same. And then, though it is against the law, I will go in to see the king. If I must die, I must die.” Esther 4:16 NLT

Cornelius fasted for 4 days.

So Cornelius said, “Four days ago I was fasting until this hour; and at the ninth hour I prayed in my house, and behold, a man stood before me in bright clothing, and said, ‘Cornelius, your prayer has been heard, and your alms are remembered in the sight of God. Acts 10:30 NKJV

A Pharisee fasted twice per week.

The Pharisee stood by himself and prayed this prayer: ‘I thank you, God, that I am not like other people—cheaters, sinners, adulterers. I’m certainly not like that tax collector! I fast twice a week, and I give you a tenth of my income.’ Luke 18:11-12 NLT

The people of Jabesh-gilead fasted 7 days after King Saul’s death.

Then they took their bones and buried them beneath the tamarisk tree at Jabesh, and they fasted for seven days. 1 Samuel 31:13 NLT

People on ship didn’t eat for 14 days because they were worried they would die in a storm.

Just as day was dawning, Paul urged everyone to eat. “You have been so worried that you haven’t touched food for two weeks,” he said. Acts 27:33 NLT

Jesus fasted 40 days, which was the longest mentioned in the Bible. I wouldn’t recommend fasting that long.

For forty days and forty nights he fasted and became very hungry. Matthew 4:2 NLT


When I first told my son that I was going to fast 21 days, he say “You are going to die!” I told him that Jesus fasted for 40 days, and he said, “But Jesus is God.” While Jesus is God, He was also fully man.

Since then, I’ve done some research and found others online who have fasted for 30, 40 or even a longer number of days. Again, I don’t recommend that anyone do that.

I’m not a doctor, but from what I understand, when you fast your body changes from burning sugar and carbohydrates, to burning fat.  When the fat is near depletion, your body starts to burn muscle. Since your heart is muscle, it is not a good thing.

So in summary, we are not required to fast, we can chose to fast at anytime, and for any length of time.

Take time to discuss the topic of fasting with your children, so they will understand. It’s a topic that is not often talked about in Sunday School.

Next week, I will review the reasons why people fast. Stay tuned.

Posted in raisedUP and tagged .

Ken Leaman

Ken Leaman has a passion for students, and for over 30 years has been volunteering within churches and other ministries, leading and mentoring students. These churches are:

Ken works for Amazon Web Services as a Support Operations Manager. Ken has also served on the boards of other non-profits like the DFW Technology Prayer Breakfast, and the DFW Help Desk Institute.

Ken, and his wife Karen, have been married for 31 years, and have a 30 year old son. They live in Allen, TX, just North of Dallas.

As Ken and Karen repeatedly witnessed many Christian students who were active within the Church walk away from their faith shortly after graduating high school, they grew frustrated.  Studies show that about 70% of young adults leave their faith after graduation, which is a huge issue since they are the future of the Church.  After much prayer and searching God's direction for many years, the Leaman's felt His calling to start a ministry to address this problem.  In 2014, they gathered like minded Christian professionals to help begin Young Adults of Worth Ministries.  We believe that this ministry is from God, and it will be blessed by Him for His glory alone.