Why do Christians fast?

Y’know, if fasting weren’t in the bible, we’d have invented it as yet another health fad. Like juice cleanses, or probiotic foods, or making sure everything is gluten-free. (Although it’s ridiculous to see so many product labels now say “gluten-free” on them. Dude, we already know beef jerky is gluten-free… or do we? Have you been secretly adding wheat this whole time?) Anyway you know some lifestyle guru would make a YouTube video, “The food-free diet,” and there ya go. Surprised it hasn’t happened yet.

Of course it is in the bible… which puts it at risk of becoming the opposite problem, where people straight-up refuse to fast because it’s “an Old Testament thing.” Because it’s part of God’s old covenant with the Hebrews which Jesus supposedly voided. Because Jesus even appears to have dismissed fasting as irrelevant:

Mark 2.19-20 KWL
19 Jesus told them, “Is the wedding party able to fast when the groom’s with them?
So long that they have the groom with them, they’re not able to fast.
20 The day will come when the groom’s taken away from them.
Then they’ll fast on that day.”

’Cause you know there are Christians who insist Jesus is always with us; he even said so. Mt 28.20 So they’d interpret “they’ll fast on that day” as only referring to the three days Jesus was dead—and now that he’s alive again, we need never fast again. In fact I’ve heard Christians claim this is the very reason they don’t fast: Why? Christ is risen!

So why do any Christians fast? Well duh, ’cause Jesus did.

Luke 4.1-2 KWL
1 Jesus, full of the Holy Spirit, returned from the Jordan,
and in the Spirit, was led into the wilderness 2 40 days, getting tested by the devil.
Jesus ate nothing in those days, and was hungry at its end.
 
Matthew 4.2 KWL
After fasting 40 days and nights, Jesus was hungry.

And Jesus fasted hardcore: He ate nothing. Wasn’t a Daniel fast. And you know some Christians would totally claim Jesus’s fast was really some form of diet; that he only gave up meat, or bread, or somehow subsisted on a diet of juniper berries and tea. But nope, Jesus ate οὐδὲν/udén, nothing. He obviously drank water, ’cause you’d die otherwise. But no food.

Since Jesus fasted, Christians fast. No, we won’t always go without food. Nor will we go without it for nearly a month and a half; most of us won’t push ourselves beyond a week. In the United States, the popular option is to forego a meal. Nope, not even a full day: One meal. Nope, not even our last meal of the day; we skip lunch, knowing we can make up for it that evening. That’s just how little self-control we have. But the reason we bother to give up something pathetic, then hypocritically act like it was a vast sacrifice, is because we know we should fast… because Jesus fasted.

And because Jesus taught us how to fast:

Luke 6.16-18 KWL
16 “When you fast, don’t be like the sad-looking hypocrites
who conceal their faces so they look to people like they’re fasting.
Amen! I promise you all: They got their credit.
17 You who fast: Fix your hair and wash your face 18 so you don’t look to people like you’re fasting,
except to your Father in private—and your Father, who sees what’s private, will repay you.”

Because fasting’s a prayer practice—it’s about using self-denial so we can focus more intently on God—we’re not doing it to show off, same as prayer. It’s between him and us, and no one else. So we fast privately. Not secretly; it’s okay to admit you’re fasting, and reschedule your business or social occasions till you’re not: Sitting there drinking water, whether you mean to do it or not, is totally showing off.

(Worse: Going to a restaurant, ordering nothing, having your server fetch you glass after glass of water, then not tipping on the grounds you ordered nothing? Not okay. If anything you should tip ’em 30 percent of what you would have spent on a meal. Oh, and do so privately—the other stingy people at your table will use your generosity as an excuse to undertip.)

Jesus taught about fasting because he totally expects us to fast. Really fast. Bad enough that people of his day would dress down and try to look all miserable when they’re going without food; now imagine how ridiculous it’d be if they behaved that way because they were only skipping lunch for a week. Nope; devout Pharisees in Jesus’s day would go wholly without food twice a week. (Devout Christians in the first century did it too.)

Because nothing declares to God, ourselves, and every spiritual force set against us, “God is more important than life itself” like fasting.