In scripture, the act of fasting is as common as prayer. To understand fasting, one must first understand food. In God's original creation, everything was made perfect. Before the fall, Adam was a vegetarian. Judaism teaches that, prior to the original sin, there was no excretion because food had nothing negative to which the body couldn't use. Rabbis teach that this convenience resumed during the days of the Exodus. Because mana "came from heaven", it was also perfect, and thus potty breaks were not necessary.
I don't know if this is true, for these teachings are from extra-Biblical sources. But it does make sense, especially when considering the layout. The camp in the wilderness was very large, more than ten miles across. A trip to the bathroom would have been painful, since Jewish scholars agree that those "trips" had to be done outside the camp.
So what is food? We understand it as "fuel" for our body. But we get a better picture by understanding what happens when we stop eating. After a few days, we start to become weak and faint. If we continue long enough without food, our sould separates from our body. We call this death. We now understand that food is what is used to connect the soul to the body. It connects our minds with our flesh, the spiritual with the natural. It is no coincidence that God describes the sacrifices as "food".
Give these instructions to the people of Israel: The offerings you present as special gifts are a pleasing aroma to me; they are my food. Numbers 28:2
God was connected with man before the fall. God and Adam walked together. It wasn't until Adam broke that connection that the sacrifices began. Adam needed an umbilical cord back to God, or he would be forever disconnected.
But the Lord God warned him, “You may freely eat the fruit of every tree in the garden except the tree of the knowledge of good and evil. If you eat its fruit, you are sure to die. Genesis 2:16-17
Here's the good news. At the moment of sin, the connection between Adam's soul and God's spirit was broken, and a new connection (knowledge) of the world was born. Animal sacrifice was God's answer to a broken chain between himself and mankind - a feeding tub if you will. This continued until the ultimate sacrifice was made by Jesus Christ. Christ connected us back to God, removing the feeding tube and making the sacrifices of NO effect.
But here's the bad news. Jesus restored our connection with God. But we are still born into a sinful world. At the moment of birth, we are connected to sin. At the moment of salvation, we are connected to God. Paul talks about these two simultaneous connections when he wrote.
I have discovered this principle of life—that when I want to do what is right, I inevitably do what is wrong. I love God’s law with all my heart. But there is another power within me that is at war with my mind. This power makes me a slave to the sin that is still within me. Oh, what a miserable person I am! Who will free me from this life that is dominated by sin and death? Thank God! The answer is in Jesus Christ our Lord. So you see how it is: In my mind I really want to obey God’s law, but because of my sinful nature I am a slave to sin. Romans 7 21-25
The purpose of the fasting isn't to remove the connection from my body to my soul. The purpose is to "weaken" it. If we can weaken the connection, we can weaken the influence. It is during this time that the flesh begins to take a protective stance instead of a destructive stance. Paul said that when he wants to do good, his FLESH wants to do the opposite. We already understand this problem. Everyone can relate to the reference of a good angel and a bad angel on our shoulders. Fasting is a way to prevent the bad angel from showing up because he is too busy looking for a sandwich.
While the flesh is screaming bloody murder, the connection to God through our "spirit" can flow uninterrupted. It is that continuous flow from God to our spirit that grows and begins to take majority share in our hearts and minds. Only when the "current" from God is stronger than our flesh, will we be able to run and NOT grow weary. Too often we focus on the lack of food or activity, but doing that misses the point. The goal of fasting isn't just to weaken the body, but to strengthen the spirit.
When Joshua was preparing for the battle at Jericho, he ordered a fast. But this wasn't a food fast. This was a speaking fast.
Now Joshua had commanded the people, saying, “You shall not shout or make any noise with your voice, nor shall a word proceed out of your mouth, until the day I say to you, ‘Shout!’ Then you shall shout.” So he had the ark of the LORD circle the city, going around it once. Then they came into the camp and lodged in the camp. Joshua 6:10-11
For seven days Joshua commanded the army not to speak a word. Joshua knew that nothing kills opportunity and victory more than negativity. To march around a city with instruments that you can't play must have looked foolish. Joshua needed murmurers and complainers like he needed a bag of pork rinds. Joshua didn't want his people to be defeated because of someone complaining it was too hot and how crazy they were for allowing God to embarrass them.
Sometimes in life, we just need to disconnect. Disconnect from the TV and it's blues. Disconnect from our "friends" and their half empty negative outlook on everything. Disconnect from family who only remember the wrong choices you've made. God's vision for your life needs to be protected and nurtured. There's always someone in line to steal it.
God told me to do something as embarrassing and stupid as walking around a city. So I went on a Joshua fast and decided not to talk about it. "Throwing it out there", when God already said it, will only invite the naysayers. When God says it, no need for a second opinion. Needless to say it worked. No one could talk me out of it. They didn't know.
A farmer went out to plant his seed. As he scattered it across his field, some seed fell on a footpath, where it was stepped on (mocked), and the birds ate it (digested in negativity and fear). Luke 8:5
When God tells you to go plant, don't tell the birds. It's hard enough that you know.