Why should God let you into Heaven?

Do you know the answer? Are you confident in your salvation?

Find out!

How Long Did Jesus Fast For?

Have you ever fasted? The Bible has a lot to say about fasting, but it is something that few evangelical Christians do. Let’s explore Jesus’ example of fasting – why He did it and for how long. What did He teach us about fasting? Why is it an essential discipline for every Christian? How does fasting empower our prayer? How do we fast? Let’s investigate!

Why did Jesus fast for 40 days?

Our information about Jesus’ fast is found in Matthew 4:1-11, Mark 1:12-13, and Luke 4:1-13. Just before that, John had baptized Jesus, and His fast immediately preceded the beginning of His earthly ministry. Jesus fasted to prepare Himself for His ministry. Fasting pulls a person away from food and other earthly things that distract our full attention on God. Jesus didn’t just go without food; he went into the desert alone, where the environment was harsh.

The point was to concentrate fully on God and commune with Him while ignoring creature comforts. Fasting empowers a person as they draw their strength from God.

Jesus never sinned, yet He was tempted to sin by Satan during His fast. Satan enticed Jesus to turn stones into bread. He knew Jesus was hungry and weak from lack of food. But Jesus’ response (from Deuteronomy 8:3) points out one reason for fasting, “Man shall not live on bread alone, but on every word that comes from the mouth of God.” When we fast, we focus on feeding on God’s Word and not physical food.”

Satan also tempted Jesus to 1) test God and 2) worship Satan in exchange for the world’s kingdoms. Jesus resisted temptation by quoting scripture. Fasting strengthens a person in fighting sin. Satan thought he was catching Jesus in a weakened state where He would be more vulnerable. But fasting-induced weakness doesn’t mean a weak mind and spirit – quite the opposite!  

What is the significance of 40 days in the Bible?

Forty days is a repeating theme in the Bible. The rainfall in the Great Flood lasted 40 days. Moses was on the summit of Mount Sinai with God for 40 days when God gave him the Ten Commandments and the rest of the law. The Bible says Moses did not eat or drink during that time (Exodus 34:28). God provided Elijah with bread and water, then strengthened by that food, Elijah walked 40 days and nights until he reached Horeb, the mountain of God (1 Kings 19:5-8). Forty days passed between Jesus’ resurrection and ascension into heaven (Acts 1:3).

Often, 40 days reflect a time of testing ending in triumph and special blessings.

Did Jesus really fast for forty days? If Moses did and Elijah possibly did, there’s no reason to think Jesus did not. Doctors believe a healthy male can live one to three months without food. Some people who have gone on hunger strikes have lived six to eight weeks.[i]

Did Jesus drink water when He was fasting for 40 days?

The Bible does not say if Jesus drank water during His fast. However, it does say that Moses did not drink for forty days. Elijah may not have drunk water in his 40-day journey unless he found a stream. In Elijah’s case, God ensured he was well-hydrated before his journey.

Some people say three days is the limit a person can live without water because most hospice patients die within three days after they stop eating and drinking. But hospice patients are dying anyway, and they stop eating and drinking because their bodies are shutting down. Most medical doctors believe one week is the limit for surviving without water, but this isn’t something that can be tested. An 18-year-old in Austria survived 18 days without food and water when the police put him in a cell and forgot about him.

What does Jesus say about fasting?

First of all, Jesus assumed that His followers would fast. He used phrases like “when you fast” (Matthew 6:16) and “then they will fast” (Matthew 9:15). Jesus never implied that fasting was optional for Christians. It was something He expected.

Jesus taught that fasting is something between the believer and God and not something to be displayed to prove one’s spirituality. Jesus said that God will see what you’re doing, and you don’t need to broadcast it to everyone else. It shouldn’t be obvious to anyone but God (Matthew 6:16-18).

John the Baptist’s disciples asked why Jesus’ disciples didn’t fast. Jesus told them that the “bridegroom” was with them – a time when people celebrate. Jesus said after He was taken, they would fast. (Matthew 9:14-15)

When the disciples asked Jesus why they couldn’t cast out a demon afflicting a boy with seizures, Jesus said, “This kind does not go out except by prayer and fasting.” (Matthew 17:14-21, Mark 9:14-29)  Some Bible versions leave out the words “and fasting” because it isn’t in all the available manuscripts. Over 30 manuscripts do include fasting, but four 4th-century manuscripts don’t. It’s in Jerome’s 4th-century translation into Latin, implying that the Greek manuscripts he translated from probably had “fasting” in them.

Jesus spent 40 days fasting before fighting the devil’s temptations and preparing for a ministry of casting out demons, so we know fasting plays an integral part in spiritual warfare. If the verse only says, “This kind comes out only by prayer,” it seems to fall flat. By “this kind,” Jesus is identifying a certain type of demon. Ephesians 6:11-18 informs us that there are ranks in the demon world (rulers, authorities). Fasting may be necessary to evict the most powerful demons.

Why should we fast?

First, because Jesus, John the Baptist’s disciples, the apostles, and the early church left an example to follow. Anna the prophetess spent all her days in the temple fasting and praying (Luke 2:37). She recognized who the baby Jesus was when she saw Him! Jesus fasted before beginning His ministry. When the church in Antioch was worshiping God and fasting, God called out Paul and Barnabas for their first missionary journey (Acts 13:2-3). As Barnabas and Paul appointed elders in each new church on that missionary journey, they fasted as they commissioned them (Acts 14:23).

“Fasting is for this world, for stretching our hearts to get fresh air beyond the pain and trouble around us. And it is for the battle against the sin and weakness inside us. We express our discontent with our sinful selves and our longing for more of Christ.” (David Mathis, Desiring God)

Fasting is a way of expressing repentance, especially for ongoing, destructive sin. In 1 Samuel 7, the people repent of worshiping idols, and the prophet Samuel gathered them to enter into a fast to turn their hearts toward the Lord and determine they will worship only Him. Wearing sackcloth was a sign of mourning, and when Jonah preached to Nineveh, the people repented, wearing sackcloth and fasting (Jonah 3). When Daniel interceded for God’s people, he fasted and wore sackcloth as he confessed the sins of the people. (Daniel 9)

In the Old Testament, people fasted not only when mourning their sins but when mourning death. The people of Jabesh-Gilead fasted for seven days of mourning for Saul and his son Jonathan. (1 Samuel 31:13).

Fasting accompanies our petitions from God. Before Esther went to her husband, the King of Persia, to request the Jews’ deliverance from the wicked Haman, she asked the Jews to gather together and fast from food and drink for three days. “I and my young women will also fast as you do. Then I will go to the king, though it is against the law, and if I perish, I perish.” (Esther 4:16)

How long should we fast, according to the Bible?

There is no set time for how long to fast. When David received the news of Saul’s death, he and his men fasted until evening (a partial day). Esther and the Jews fasted for three days. Daniel had a period of fasting that lasted less than a day. In Daniel 9:3, he said, “I turned my attention to the Lord God to seek Him by prayer and petition, with fasting, sackcloth, and ashes.” Then, in verse 21, he says, “While I was still praying, Gabriel, the man I had seen in the earlier vision, came to me in swift flight about the time of the evening sacrifice.” Gabriel told him that as soon as Daniel started praying, “an answer went out, and I have come to tell you, for you are highly precious.”

But in Daniel 10, he said he fasted for three weeks. However, this wasn’t a complete fast from food: “I ate no rich food, no meat or wine entered my mouth, and I did not anoint myself with oil until the three weeks were completed.” (Daniel 10:3)

And, of course, we know that Moses and Jesus (and probably Elijah) fasted for 40 days. When you decide to fast, seek God’s guidance in how you should fast and how long.

Also, of course, you should consider any health conditions (like diabetes) you may have and the physical requirements of your job and other responsibilities you have. For instance, if you’re on your feet all day at work or serve in the military, you might want to only fast on your days off or engage in a partial fast.

How to fast according to the Bible?

The Bible gives several examples of fasting:

  1. Total fasting with no food
  2. Fasting for part of a day (skipping one or two meals)
  3. Partial fast for a longer time: going without certain foods, like meat, wine, or rich foods (like desserts and junk food).

Seek God’s direction for which type of fasting is best for you. Medical conditions and medications that need to be taken with food can factor in. Suppose you have diabetes and take insulin or glipizide. In that case, you should not skip meals but can modify your meals, such as eliminating meat and/or desserts.

You might also consider fasting from certain activities to give your full attention to prayer. Pray about fasting from TV, social media, and other entertainment.

You might want to cycle through all three types of fasting depending on how active you are. For instance, you might do a complete fast on Sunday and a partial fast during the week.

The Bible also talks about individual fasting, like Anna or Daniel, and corporate fasting with others, such as in the early church or with Esther and the Jews. Consider fasting and praying as a church or with like-minded friends about certain things, like revival!

The power of prayer and fasting

When you feel overwhelmed by the situations in your life or what’s happening in the country or worldwide, that’s a strategic time to fast and pray. Most of us have untapped spiritual power because we neglect fasting. Fasting and prayer can turn our circumstances around, break down strongholds, and turn our country and world around.

If you feel spiritually dull and disconnected from God, that’s also an excellent time to fast and pray. Fasting will reawaken your heart and mind to spiritual things. God’s Word will come alive as you read it, and your prayer life will explode. Sometimes, you might not see results while fasting, but when the fast ends.

When entering a new chapter in your life, such as a new ministry, marriage, parenthood, a new job – praying and fasting is a fantastic way of getting it started on the right footing. That’s what Jesus did! If you sense God has something new, spend time praying and fasting to be sensitive to the Holy Spirit’s leading.

Examples of fasting in the Bible

  1. Isaiah 58 spoke of the frustration of God’s people when they fasted, and nothing happened. “Why have we fasted, and You do not see?”

God pointed out that at the same time they were fasting, they were oppressing their workers, and they were quarreling and striking each other. God explained the fast He wanted to see:

“Is this not the fast that I choose: to release the bonds of wickedness, to undo the ropes of the yoke, and to let the oppressed go free, and break every yoke?

Is it not to break your bread with the hungry and bring the homeless poor into the house; when you see the naked, to cover him; and not to hide yourself from your own flesh?

Then your light will break out like the dawn, and your recovery will spring up quickly; and your righteousness will go before you; the glory of the LORD will be your rear guard.

Then you will call, and the LORD will answer; you will cry for help, and He will say, ‘Here I am.’” (Isaiah 58:6-9)

  1. Ezra 8:21-23 tells about a fast that Ezra the scribe called as he was leading God’s people from the Babylonian exile back to Jerusalem.

“Then I proclaimed a fast there at the river of Ahava, to humble ourselves before our God, to seek from Him a safe journey for us, our little ones, and all our possessions . . . So we fasted and petitioned our God about this, and He granted our request.”

  1. The book of Jonah tells how God sent the prophet Jonah to Nineveh to preach to the people. Jonah did not want to go because Nineveh was the capital of Assyria, a nation that had repeatedly attacked Israel, committing cruel atrocities. Three days in the belly of the whale convinced Jonah to obey God. He went to Nineveh and preached, and the king called a fast of the entire city:

“Let no man or beast, herd or flock, taste anything at all. They must not eat or drink. Furthermore, let both man and beast be covered with sackcloth, and have everyone call out earnestly to God. Let each one turn from his evil ways and from the violence in his hands. Who knows? God may turn and relent; He may turn from His fierce anger, so that we will not perish.” (Jonah 3:7-9)

            God did listen and spared Nineveh when He saw their sincere repentance and fasting. 


In his book A Hunger for God, John Piper says:

“The greatest enemy of hunger for God is not poison but apple pie. It is not the banquet of the wicked that dulls our appetite for heaven, but endless nibbling at the table of the world. It is not the X-rated video, but the prime-time dribble of triviality we drink in every night… The greatest adversary of love to God is not his enemies but his gifts. And the most deadly appetites are not for the poison of evil, but for the simple pleasures of earth. For when these replace an appetite for God himself, the idolatry is scarcely recognizable, and almost incurable.”[ii]

Jesus and the early church made it clear that fasting was part of normal Christianity. But we have become so addicted to comfort and indulging ourselves that we often think of fasting as weird or something for the past. Fasting is an essential spiritual discipline if we truly want to focus on God, purify ourselves of the sin that holds us back, and see revival in our lives, churches, and nation.

[i] https://www.medicalnewstoday.com/articles/how-long-can-you-go-without-food#how-long

[ii] https://www.desiringgod.org/books/a-hunger-for-god

0 comments… add one

Leave a Comment