Elmer Towns had a big problem three decades ago after he moved to Lynchburg, Va., to help a Baptist preacher named Jerry Falwell start the school that grew into Liberty University. Month after month, Towns faced two house payments -- a real family crisis. Thus, the veteran Bible professor decided to try something that he considered a radical, "Old Testament thing." In addition to praying that someone would buy the house back in Chicago, Towns and his wife Ruth began fasting on the day that mortgage was due.

Not much happened, but they kept praying and fasting.

After a year, the house sold and Towns has been pondering this question ever since: What role did their fasting play in solving this personal problem?

"What I have learned is that there is much more to fasting than trying to get something from God, because we cannot say what God will do," said Towns, the author of 100-plus books and dean of the School of Religion at Liberty.

"You are really fasting because you want a closer relationship to God. ... There are fasts where you are seeking an end result -- like the deliverance of a person from addiction. But that is not the norm. That's not the main reason God wants us to fast."

These kinds of mysteries have driven Towns to do something that may sound strange for an evangelical Protestant. He has written three books about fasting, including the recent "The Beginner's Guide to Fasting," and has already finished a fourth book on this topic.

Fasting, of course, is a familiar practice for Jews, who observe a strict fast on Yom Kippur ("Day of Atonement"). Muslims fast from sunrise to sunset during the month of Ramadan and believers in many other religions also practice forms of fasting.

Roman Catholics and Eastern Orthodox Christians fast several times during the church year, especially in the pre-Easter season of Lent -- which began this past week. Some modern Catholics continue to fast from meat during Lent, while the Orthodox strive not to eat meat or dairy products.

This practice -- eliminating specific forms of food from the diet -- is one of several different forms of fasting found in the Bible and in religious history, noted Towns. In the Book of Daniel, the prophet and his friends only ate vegetables and water for 10 days. The leader of the Methodist renewal movement, John Wesley, often fasted for 10 days before major conferences, eating only whole-grain breads and drinking water.

Another common practice, which Towns considers a "normal" fast, is to eat nothing, while continuing to drink liquids. The Gospel of Luke observes that during a 40-day fast Jesus "ate nothing and afterward, when he had ended, he was hungry."

An "absolute" fast, said Towns, eliminates both solid food and liquids, as in St. Paul's three-day fast after his conversion on the Damascus road. This strict form of fasting is not for beginners and never should exceed three days, he said. On Mount Sinai, Moses is said to have survived a 40-day fast without food or drink -- which would clearly be miraculous.

Believers who are new to fasting should seek guidance from experienced clergy and even from doctors, stressed Towns. The bottom line: It isn't physically or spiritually wise to "put God to the test by rushing off and doing something irrational," he said.

In the past decade or so, interest in spiritual disciplines such as fasting is on the rise among many Protestants, including evangelicals and those in Pentecostal or "charismatic" movements, said Towns. This is interesting because, at the same time, many Americans seem anxious not to be labeled as religious "fanatics," "nuts" or "extremists."

Yet many Americans seem open to new forms of religious experience.

"I think that there's a growing interest in spirituality among all kinds of people -- people inside the church and people outside the church, as well," said Towns. "Some people are willing to try all kinds of things right now, including some things that I think are very dangerous.

"People may hear about fasting and say, 'That sounds interesting. That sounds powerful. I think I'll give that a try.' ... The issue is whether they have the commitment to stick to it. I'm concerned that most people aren't willing to pay a price to experience the presence of God."