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.
You don’t have to pray alone. Have your prayer submitted to the Holy Land as well as churches, monasteries, and prayer groups worldwide who will lift your intentions to God and pray on your behalf.
From the Holy Sepulchre in Jerusalem to sacred sites across the globe, your prayer will be shared and remembered.
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.
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.
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.
Electrolytes. Please add them - salt, potassium, and magnesium can really make a difference. And track warning signs like dizziness, heart palpitations, confusion, and fainting.
You will not be only fasting, the other big part is resisting temptation and leaning fully into God - Like what Jesus did. And taking all that on yourself is a serious spiritual commitment.
You really do need to keep both your physical and spiritual health in the picture here.
Have you tried a shorter fast on water before? Any idea if your body can handle a water-only fast for that long? It might be worth adding some nutrients to the process.
The intent behind fasting (especially for Christians) is to deepen your relationship with God and gain clarity you wouldn’t get otherwise.
It shifts your focus toward prayer and reliance on God’s strength instead of your own.
Listen to your body, though. Physical weakness during fasting will push you deeper into spiritual perseverance, which is part of the process, but there’s a line.
Anyway, your body is a temple. Taking care of it honors God just as much as the fast itself does. Don’t forget that.
If I remember correctly, in the early church, around the 1st-2nd century, communal fasting was typically twice a week, on Wednesdays and Fridays. Not these marathon stretches.
The point was showing up consistently, over a whole lifetime. Which, yeah. Much more my speed.
Full disclosure, though, I once tried a three-day fast, and by hour 30 I was standing in my kitchen holding a jar of peanut butter.
So take my input with a grain of salt.
But that twice-a-week rhythm makes more sense to me.
Even Jesus had the Spirit sustaining him during those 40 days, and I’m not sure our bodies are meant to handle that kind of extended fast without divine support.
Maybe something like a Monday fast each week would be more sustainable for most people? Just a thought.
And I’m curious what others think about the milk/protein approach for longer fasts too…
Jumping straight into 40 days is not a good idea. Just being straight with you.
I did it myself, but only after working through 14, 21, and 30-day fasts first, each one something God specifically led me into. Not something I just decided on my own.
The breakthroughs are real, and the spiritual authority you gain is unlike anything else - but it is serious business.
I used each mealtime for prayer instead. And look, there’s no condemnation if you don’t complete the full 40.
God sees your heart in this.
Just worth counting the cost first. I lost around fifty pounds and much of my hair.
A 40-day fast is a bit too long and too much for your mental and physical health.
1 Corinthians 12 reminds us we’re all part of one body, and taking care of yourself matters too - not just for your own sake but so you can keep showing up for the people around you.
not all food.
Even Jesus had the Spirit sustaining him during those 40 days, and I’m not sure our bodies are meant to handle that kind of extended fast without divine support.
Just a thought.