Of all the spiritual tools in our toolkit, fasting has to be the most unusual one. Fasting has been practiced for thousands of years in many different ways for many different purposes, including religious reasons, health and even as expressions of protest. Even among and within the world’s religions fasting means something different.

So what is fasting?

A common dictionary definition is that it is abstinence from food or drink or both for ritualistic, mystical, ascetic or other religious or ethical purposes. The abstention may be complete or partial, lengthy or of short duration.

When you look at how different religions incorporate fasts into their beliefs, you can understand why the dictionary defines fasting this way.

But how does the Bible define fasting?

We can learn much about fasting from reading the passage that describes the one day in the year, God absolutely commands His people to fast.

“Also on the tenth day of this seventh month there shall be a day of atonement: it shall be an holy convocation unto you; and ye shall afflict your souls …. And ye shall do no work in that same day: for it is a day of atonement, to make an atonement for you before the Lord your God. For whatsoever soul it be that shall not be afflicted in that same day, he shall be cut off from among his people” (Leviticus 23:27-29).

God commands His people “afflict” their souls for a 24-hour period on the Day of Atonement. What does that mean? Let the Bible answer!

King David tells us: “But as for me, when they were sick, my clothing was sackcloth: I humbled my soul with fasting …” (Psalm 35:13). The margin reads afflicted for humbled. Again David writes, “When I wept, and chastened my soul with fasting, that was to my reproach” (Psalm 69:10).

There are other examples in the Bible that demonstrate how the words afflict and fast are interchangeable. For more proof, you can read examples of this in Isaiah 58 and Ezra 8.

To afflict one’s soul is to fast: That means to abstain from all food or drink for a certain period of time.

It is a complete, not partial, abstinence. This is made clear by the command surrounding the Day of Atonement. An example of complete abstinence can be found in Jonah 3.

Jonah was a prophet of God sent to warn the city of Nineveh that it would be overthrown in 40 days. The people of Nineveh actually believed the warning and acted to avert disaster: “So the people of Nineveh believed God, and proclaimed a fast, and put on sackcloth, from the greatest of them even to the least of them” (Jonah 3:5). Then the king passed a law to enforce the fast. In it he made clear what it meant to fast: “And he caused it to be proclaimed and published through Nineveh by the decree of the king and his nobles, saying, Let neither man nor beast, herd nor flock, taste any thing: let them not feed, nor drink water” (verse 7).

Once again, you see the Bible defines a fast as abstaining from all food and drink. It’s not eliminating your favorite food for a month; neither is it periodically skipping a meal, nor is it only drinking liquids while refraining from eating.

Finally, when defining a fast it is important to examine the motivation behind the fast. A proper spiritual fast isn’t the same as a health fast. It is much more than abstaining from food. A true spiritual fast is fasting in order to humble ourselves so that we might draw closer to God.

The Bible explains: “Therefore also now, saith the Lord, turn ye even to me with all your heart, and with fasting …” (Joel 2:12). To God, a fast isn’t a show; it’s a method that helps us turn our hearts to Him, if we do it in the right attitude.

With that in mind, we gain the full, biblical definition of a fast: abstaining from all food and drink to humble ourselves and draw closer to God.

We have many articles on why God wants us to fast and how to fast. If you want to learn how to fast, or if you desire a deeper and closer relationship with God, be sure to read further on this subject.