“Fasting” is a penitential practice that goes back at least to Moses. He fasted for 40 days while on top of Mount Sinai. The people of Israel fasted during their 40 year wandering in the wilderness. Elijah fasted on his way to the mountain of God. Jesus fasted 40 days in the wilderness.
“Fasting” is a discipline that ranges from going completely without food and water for a short period of time (24 hours) to going without some normal part of one’s usual diet. Traditionally Lutherans have “fasted” on Good Friday by substituting fish for meat on that day in observance of the offering of the “Sacrificial Lamb,” Jesus Christ, on the cross.
In the early days of the church “fasting” was associated with candidates preparing for Baptism during the 40 days of Lent. Today it ranges from someone giving up alcohol or chocolate (something considered an exess) for the whole Lenten period to going without food for a day or two and giving the money saved on food to world hunger. This is a popular Lenten program for youth groups.
The purpose of fasting is to commit the body and mind to a time of penitence (confessing one’s sins) by cleansing the body of what is unclean. Fasting is also a way for an individual to become one with the sufferings of the world.