Christians Fasting for 40 Days

Has anyone tried a 40-day fast?

I’ve been doing a water-only fast. Like the forty days Jesus spent in the wilderness, I wanted to take even a small step in that direction, to understand the kind of sacrifice and resolve that took and maybe draw closer to God in the process. I don’t know if I can make it the whole way, but I’ll go as far as I can, and if I can’t do all 40, maybe a modified version.

I know that caring for the body God gave you matters too. Prayer already feels different when your body is weaker, but I have the fasting prayer points to help.

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A full 40 days is tough. I hope everything goes smoothly.

I read that Bill Bright (the founder of Campus Crusade) did a 40-day fast - he wasn’t a beginner. He had been doing one- to four-week fasts for years, yet he added juice midway through.

So, maybe include juice or broth along the way.

I’m not trying to talk you out of the spiritual commitment. Just maybe talk to a doctor first?

This is a major change to your whole system. Your electrolytes can become depleted, which is really dangerous, so be extra cautious if you’re outside.

Also, be ready for some real physical side effects.

Your body switches to burning fat within a few days, and not much longer, you start losing muscle mass too. Probably about two-thirds of the weight lost during fasting is lean mass, not fat. I’m no doctor, but just Google the muscle loss side effects of fasting, and you’ll find tons of studies.

Oh, and look into refeeding syndrome before you break the fast.

I know that David Blaine did his 44-day water fast (with doctors carefully managing his reintroduction of food), and he developed hypophosphatemia and needed IV phosphorus.

If you just eat a big meal after 40 days, you can trigger heart failure. Not exaggerating.

God bless you!

This is a big commitment!

So basically, the early church practiced fasting regularly.

Wesley was so committed to fasting that he made early Methodists fast every Wednesday and Friday, and he actually refused to ordain anyone who wouldn’t commit to that schedule.

Another example is Daniel.

Daniel 10:2-3, where he mourned for three weeks and ate no meat or wine, no choice foods.

And the three men in the Bible who did the full 40-day fast were Moses, Elijah, and Jesus. Specific callings.

You mentioned prayer feels different when your body is weaker.

Well, that is physically gonna be the case, and you might get some spiritual feeling from it too, but I’d say don’t let weakness become the point.

Fasting without prayer is just going hungry. “If you’re not spending that time in prayer, you are not fasting, you are dieting.”

If you end up needing to modify the fast, there’s strong biblical precedent for that too - a partial fast isn’t somehow lesser.

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Reading your post and praying for you.

Keep a journal if you’re not already. This kind of experience is perfect for writing down what God is showing us during the fast.

I’ve never done a 40-day fast, but I did a 10-day one, and after day 3, my physical craving went away. People who have done longer fasts say the same.

Even Scripture says that when Jesus fasted for 40 days, He only felt hungry at the end of the fast (Matthew 4:2).

I heard from a guy who completed the full 40 days on water that after 30 days, he needed a midday nap, but he was not weak.

His biggest challenge was mental. He constantly thought about the foods he missed, and it weighed heavily on him.

Have you watched any of Pastor Vlad on YouTube? He said most people’s biggest failure in finishing a 40-day fast is mental, not physical. Worth watching his stuff.

All that said, when Satan attacked Jesus during His fast, it was in His mind and emotions.

So maybe prepare for discouragement, strong urges to quit, and emotional swings that might come out of nowhere.

Every person’s experience is different, but IMO the fatigue thing is real. Your body will need electrolyte support, especially sodium.

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Your body can handle it. That much I’m pretty sure of - there are modern examples of people going even longer than 40 days on water alone.

Whether that reflects exactly what Scripture describes - I can’t say for sure.

But the physical challenge itself is within human reach.

I’m on week 2 of my water fast. Curious how yours went - mine’s been harder than I expected.

Many pastors do water-only fasts for this long, and they’re certainly not Jesus.

And if He could walk on water, heal the sick, raise the dead, I’m pretty sure He could outlast the average person on a fast.

That said, listen to your body and consult a doctor before you start.

A 40-day water-only fast isn’t how Christians have traditionally done extended fasts.

Lent is 40 days, yes - but it’s about cutting out specific food groups :meat_on_bone: :cheese: :wine_glass: not all food.

The Orthodox avoid meat, dairy, oil, and alcohol during that time. It’s truly strict, but you can still eat and go about your day.

A single-day complete fast is one thing. Forty days of total food deprivation is something else entirely.

Your body is a temple of the Holy Spirit and an icon of God. You have an obligation to maintain it.

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Are you really planning on doing this?

My grandmother tried an extended fast when she was in her sixties.

Two weeks in, she ended up in the hospital.

God gave us these bodies to care for, not to push them beyond what they can handle.

Gradual is the way. Think of it like training for a marathon - you add a day each week until your body (and spirit) can handle the longer fast.

My job limits me to a day or two at most, but even that has been enough.

Consistent weekly fasting has done more for my walk with Christ and my ministry than anything else I’ve tried.

Fasting was practiced in many different ways during Jesus’ time.

The Pharisees fasted on Mondays and Thursdays.

The Essenes had their own routines.

Early Christians fasted on Wednesdays and Fridays according to the Didache.

So there was never a single standard.

The 40-day fast seems more symbolic to me. It is basically about reflecting Israel’s wilderness experience.

“Is not this the fast that I choose… to share your bread with the hungry?” (Isaiah 58:6-7).

Maybe think about donating what you would have spent on food.

Electrolytes. Please add them - salt, potassium, and magnesium can really make a difference. And track warning signs like dizziness, heart palpitations, confusion, and fainting.