Jesus fasted.
Among the gospel writers, only Matthew (4) and Luke (4) mention it.
After fasting forty days and forty nights, he was hungry.
Jesus, full of the Holy Spirit, left the Jordan and was led by the Spirit into the wilderness, where for forty days he was tempted by the devil. He ate nothing during those days, and at the end of them he was hungry.
It’s one of the few places in scripture that fasting is mentioned apart from prayer.
I think that’s for the same reason that prayer — and God Himself, for that matter — are never mentioned in the book of Esther, though fasting is. If we can’t see them there, we’re not reaching the right conclusions. If Esther and her people fasted without praying, then all they did was go on a diet. If justice for her people happened without God, then coincidence is king of the universe, because Hamaan was evil and deserved the consequences of his murderous bigotry.
Likewise, if Jesus went out into the wilderness to prepare for His ministry and fasted without praying, then He was simply on a radical weight-loss program, perhaps designed to make Him look like an ascetic shaman. If He withstood even just the temptation to create food for Himself without the strength that comes from communing with God, then prayer has no power and He was not God’s Son — only a starving mystic with extraordinary self-control.
I’ve blogged a little about fasting before. I’m no expert on it. There are right ways to do it. There are wrong ways to do it. Books have been written about it. Some are doubtless more valuable than others.
With or without reading them, I think we can draw the conclusion from scripture that God’s people fasted, and almost without exception, accompanied their fasts with prayer. Sometimes they expressed petitions and desires. Often they simply praised Him. Other times they mourned and/or repented. They expressed the depth of their need for and dependence on God by going without physical nourishment. In this way, they told Him that He was more important to them than food; that their god was not their stomachs; that they hungered and thirsted for His righteousness; that they had tasted and seen that the Lord is good; that their communication with Him was sacred and private and not for the benefit of being seen by others and regarded as somehow holy for what they had done without.
But if we think we can follow Jesus, minister as He did, resist temptation, and do the things He did while regarding this practice as optional — I believe we’re fooling ourselves.
Fasting is not simply a quaint and ancient custom or a passé commandment from a set of laws that have all served their purpose.
Fasting is a recognition of God’s providence.
It is the physical, expressing the spiritual.
It is hunger, declaring desire.
It is emptiness, seeking fulfillment.
It is the way Jesus chose to prepare for His life of ministry, and to build the strength of His character, His self-discipline before facing forty days of temptation from Satan’s seemingly undivided attention.
You see, that’s what the other synoptic gospel writer, Mark (1), does not fail to communicate:
At once the Spirit sent him out into the wilderness, and he was in the wilderness forty days, being tempted by Satan. He was with the wild animals, and angels attended him.
Nor was that likely the last time Satan tried:
When the devil had finished all this tempting, he left him until an opportune time. ~ Luke 4:13
If fasting was a source of spiritual strength that could empower Him to journey all the way from the TransJordan to Galilee (see the next verse) … to withstand temptations to satisfy self, seize easy power, trade faith for fact … then why do we ignore, neglect or even reject it?
Following Jesus means fasting and prayer.
Blog In My Own Eye 
Good questions, KB. I don’t feel like I have much experience with fasting, or really even know all that much about it. I don’t think it’s something we talk about often. And I’ve never done it for more than about 30 hours at a time. But I will share of my limited experiences with it:
Whenever Trey Morgan hosts his “Dump Day” fundraiser, I usually participate in that 30-hour fast, which serves as a good opportunity for me to pray for the success of that ministry and to remember to thank the Lord for all the ways He’s blessed me.
Back in 2006-2007, when I was still pretty new to PV, I often felt a little empty, spiritually. I came to church because that’s what I was supposed to do, but I didn’t necessarily want to be there. Didn’t really have the same desire for the Lord that I used to, even just a couple of years back before that, when I was in college. At some point during that time frame, I took to fasting once a week. Usually on Wednesdays. Not sure how long that lasted, I don’t remember. My guess is anywhere from 3-6 months. It was the first time I’d ever really done it. Whenever I was hungry, my prayer would simply be “Lord, please help me to hunger like this for You.” I’m not sure what else to say about that experience except that not only did He give me that desire, He’s also filled it (continuing to fill it) with His Presence.
A couple of years later, I did something that was more along the lines of a Lenten fast, where you give up one thing for a period of time. Except it wasn’t Lent. It was summertime, and into the early fall. And although I gave up sodas, this fast was different from the other that I had done, in that I didn’t feel like I was “giving up” anything. I started it at the beginning of one of the Beth Moore studies that I participated in, where–I think–she encouraged us to do so. She began that study with a look at a passage in Numbers 15, instructing the Israelites to put blue tassels on their clothing, to help them to remember the Lord, to obey His commands, and to be consecrated to Him. She encouraged something similar for us, with the wearing of a blue ribbon/yarn around our wrists for the duration of the study. (I had difficulty making my blue ribbon stay. So I switched to an elastic blue hair band, which worked beautifully.) That was a helpful practice, one I’ve taken up a couple of times since, just to have something that I can look at every day–multiple times a day–to serve as a reminder that I have been made holy to the Lord, and I should do my best to live as such. The fasting aspect of that just felt like an added dimension to that. I wasn’t so much sacrificing, as I was setting aside something that I didn’t need.
The Purpose of Spiritual Fasting
While many people fast to lose weight, dieting is not the purpose of a spiritual fast. Instead, fasting provides unique spiritual benefits in the life of the believer.
Fasting requires self-control and discipline as one denies the natural desires of the flesh. During spiritual fasting, the believer’s focus is removed from the physical things of this world and intensely concentrated on God. Put differently, fasting directs our hunger toward God. It clears the mind and body of earthly attentions and draws us close to God. So, as we gain spiritual clarity of thought while fasting, it allows us to hear God more clearly. Fasting also demonstrates a profound need for God’s help and guidance through complete dependence upon him.
What Spiritual Fasting is Not
Spiritual fasting is not a way to earn God’s favor by getting him to do something for us. Rather, the purpose is to produce a transformation in us—a clearer, more focused attention and dependence upon God.
Fasting is never to be a public display of spirituality—it is between you and God alone. In fact, Jesus specifically instructed us in Matthew 6:16-18 to let our fasting be done privately and in humility, else we forfeit the benefits.