Today is the Day of Atonement, which is known in Judaism as "Yom Kippur." I am fasting on this day because I believe that the ritual has much to teach me, a Christian (see also Jim West's post on Yom Kippur). I have treated Yom Kippur as a time for fasting, rest, reflection, prayer, and Bible study for many years.
Why do I fast? Jesus himself acknowledged the importance of fasting in the Sermon on the Mount, in which he said "when you fast" (Matthew 6:16-18). Was he telling the disciples that they had to fast? I'm not entirely sure. The Greek word translated as "when" in the KJV is "hotan," which can mean "whenever." Jesus may be saying to his disciples that fasting is not a requirement, but that they should fast a certain way when they choose to do so.
What is interesting is that v 17 seems to conflict with certain Jewish Yom Kippur rules. Jesus tells his disciples to anoint their heads and wash their faces whenever they fast. Mishnah Yoma 8:1, however, prohibits Jews from anointing or washing themselves on Yom Kippur. They are truly to afflict themselves on that day. Jesus may not have been discussing the Day of Atonement in this passage. After all, he says that his disciples should not appear to men to fast. For Jesus in the Sermon on the Mount, fasting should be strictly between the faster and God, not a means to impress others. On Yom Kippur, however, all Jews knew that every other Jew was fasting, so there was no need to keep it a secret.
But Jesus acknowledged that his disciples may wish to fast. The Day of Atonement is really the only time that I have to do so. I have a hard time fasting when school is in session, since I cannot concentrate on my work with intense hunger or thirst. So I set aside a day when I get to fast and focus on God in the process.
Why fast? For the Jews, Yom Kippur was the day when the sins of Israel were expiated and removed. God was holy and righteous, so he would not dwell with Israel when she had moral corruption. God was also removing physical impurity that accumulated onto his sanctuary. Anything associated with a loss of life or strength (e.g., corpses; a loss of semen; even childbirth, when a mother risked her life and lost blood) could defile God's sanctuary. Maybe God wanted to disassociate himself from death in such rules. This may sound evangelical, but perhaps he was saying that death and pain in childbirth were not a part of his original creation (Genesis 2-3). Could God have been reminding Israelites of original sin on Yom Kippur, in addition to the sins that they themselves did? And, ironically, God dissociated himself from sin and death through death, that of an animal. Likewise, according to Christianity, God defeated sin and death in part through the crucifixion of Christ.
But the Israelites fasted to demonstrate their serious response to what was occurring. If they were acknowledging that the world was fallen, then they were communicating that this was serious and tragic indeed. And they were showing their sorrow for their own sin. As a Christian who fasts on the Day of Atonement, perhaps I can learn that this world breaks God's heart and is not entirely what he desires it to be. That is why we pray "Thy Kingdom come, thy will be done on earth as it is in heaven." And I can acknowledge that I myself need God to forgive my sins.
Interestingly, many evangelicals say, "God cannot tolerate sin." And even I said above that God would not dwell with a morally corrupt Israel. Yet, he often did. Jacob had idols in his camp, but God blessed him. Northern and Southern Israel were around longer than the United States was a nation, even as they did things that God clearly hated. Still, there was a time in both situations in which God hit the podium and said, "You need to deal with your sin, now! I hate sin, and so should you." The Day of Atonement was a time to focus on that message, and to do so with solemnity.
Fasting also has other benefits. I can focus on God more because I do not have to spend time eating. Fasting also reminds me that I am a fragile creature, something I often forget in my youth.
Well, I have ten minutes left before my fast is over. Writing this has helped me reflect on lessons that I can learn from the Day of Atonement. Hopefully, this post has also edified you.
God bless you!