BOB ABERNETHY: On our calendar this week, Ash Wednesday on the 17th, the first of the 40 days of Lent in the western Christian year, leading up to Easter. For Eastern Orthodox Christians, Lent begins Monday the 22nd.

On Ash Wednesday, as in Rome last year, many Christians received the sign of the cross in ashes on their foreheads or heads, a symbol of repentance and mortality. All the most ancient Christian traditions practice this and other Lenten observances, such as fasting, and now more and more Protestants, among them evangelicals, are observing Lenten fasting, too. One of the leaders of the movement is Richard Foster, author of the best-selling CELEBRATION OF DISCIPLINE. At his office in Denver, Dr. Foster spoke with us about fasting.

Dr. RICHARD J. FOSTER (Author, CELEBRATION OF DISCIPLINE): Fasting is the voluntary denial of an otherwise normal function for the sake of intense spiritual activity. You will see that in experiences of fasting, you begin to focus on things that are greater than yourself and learning to be sustained by things beyond food itself.

ABERNETHY: Catholics are obliged to abstain from meat on Ash Wednesday, Good Friday, and all Fridays in Lent and to eat just one full meal on those fast days. Foster recommends occasional abstinence from all food, but he says start slowly.