During the Lenten season, and important times in our lives, Christians choose to fast. Fasting, today, is the choice to give up something for a 40 day period. I can still remember the children's sermon back when I was only 9 or 10 years old. It was the Lenten season and the adult leader passed every kid a bag of chocolate coins. Then, to a bunch of children, the leader told us we couldn't touch the chocolate for 40 days. (Plus, the Sundays. Lent really excludes Sundays, but we were supposed to abstain for those days too.)
The only goal this really accomplished was making me want chocolate even more. I spent Lent staring longingly at the bag. I opened the bag and counted the coins. I touched them every night. I wanted those candies.
Christian fasting is symbolic of Jesus' 40 days in the desert. Jesus' 40 days in the desert is symbolic of the Israelite's 40 years in the wilderness. If we really want to understand the purpose of fasting we should look to the purpose of the Israelite time in the wilderness. The Israelites didn't spend 40 years in the desert with God hanging some sweet treat over their head. The Israelites were not living with less. Remember, they were slaves before they spent their time in the wilderness so they actually had more in the wilderness: freedom.
The purpose of the wilderness time was preparation. The Israelites couldn't handle the Promised Land. It was through 40 years of controlled freedom they gained the skills to be able to lead themselves. If we spend the time focusing on what we are without we are making idols out of our want. Instead, we should spend the time seeking out what we need. Fasting is a time to get the tools for the work God is calling us to. Fasting is a time to learn the skills for the job ahead. We go without because it gives us focus, not because it turns our focus away.