Christian fasting isn’t some kind of a “work” that’s commanded by Christ or required by Scripture. Fasting, in the biblical sense, is the abstaining from food and drink for a spiritual reason. However anything you can temporarily give up in order to better focus on God can be considered a fast (1 Corinthians 7:1-5). In the Old Testament era, the Jews fasted frequently, though there was only one fast prescribed by the law. Once each year, on the Day of Atonement, the Hebrews were to “afflict” their souls (Leviticus 16:31), which meant fasting (cf. Isaiah 58:3).
Though there are no compulsory fasts required of Christians today, the New Testament seems to take for granted that children of God would see the need to fast occasionally.
Is Fasting Obligatory for Christians?
The Mosaic Law ordered the Jews to “afflict [their] souls,” that is, to fast, once a year on Atonement Day. (Leviticus 16:29-31; Psalm 35:13) This was the only fasting that Jehovah ever commanded his people to do.* Jews who lived under the Mosaic Law would have obeyed that command. But Christians are not required to observe the Mosaic Law.—Romans 10:4; Colossians 2:14.
Since Jesus fasted following his baptism and not before his death, the fact that some religions observe Lent in the weeks preceding Easter may seem strange. However, a 40-day fast in the early part of the year was common among ancient Babylonians, Egyptians, and Greeks. The “Christian” custom was evidently borrowed from them.
The 40-day fast of Lent is said to commemorate the 40-day fast of Christ. Yet, Jesus never commanded his disciples to commemorate his fast, nor is there any evidence that they did so. The first reliable mention of the 40-day fast before Easter is thought to be in letters of Athanasius, dated 330 C.E.
Am I in sin if I choose not to?
No. But the Bible assumes we will fast. Jesus simply takes it for granted (Matt. 6:16-18 / “when you fast”). In Mark 2 we see the same emphasis. When the Pharisees queried why Jesus’ disciples didn’t fast, he explained it in terms of his own physical presence on earth. “The days will come,” he said, “when the bridegroom is taken away from them, and then they will fast in that day.”
However, that means that fasting is recommended as a part of our spiritual growth. The Book of Acts records believers fasting before they made important decisions (Acts 13:4; 14:23). Fasting and prayer are often linked together (Luke 2:37; 5:33). Too often, the focus of fasting is on the lack of food. However, the purpose of fasting is to take our eyes off the things of this world and instead focus on God. Fasting is a way to demonstrate to God and to ourselves that we are serious about our relationship with Him.
Fasting should be limited to a set time, especially when the fasting is from food. Extended periods of time without eating are harmful to the body. Fasting is not intended to punish our flesh, but to focus on God.
Focus Deeper on God
Fasting should not be considered a “dieting method” either. We shouldn’t fast to lose weight, but rather to gain deeper fellowship with God. Yes, anyone can fast. Some may not be able to fast from food (diabetics, for example), but everyone can temporarily give up something in order to focus on God. Even unplugging the television for a period of time can be an effective fast.
Although fasting is not required in Scripture, but it’s highly recommended. The primary Biblical reason to fast is to develop a closer walk with God. By taking our eyes off the things of this world, we can focus better on Christ. “When you fast, do not look somber as the hypocrites do, for they disfigure their faces to show men they are fasting. I tell you the truth, they have received their reward in full. But when you fast, put oil on your head and wash your face, so that it will not be obvious to men that you are fasting, but only to your Father, who is unseen; and your Father, who sees what is done in secret, will reward you” (Matthew 6:16-18).
A Lifestyle of Servant Living
Christian fasting is more than denying ourselves food or something else of the flesh – it’s a sacrificial lifestyle before God. In Isaiah 58; we learn what a “true fast” is. It’s not just a one-time act of humility and denial before God, it’s a lifestyle of servant ministry to others. As Isaiah tells us, fasting encourages humility, loosens the chains of injustice, unties the chords of the yoke, frees the oppressed, feeds the hungry, provides for the poor, and clothes the naked. This concept of fasting isn’t a one day thing – it’s a lifestyle of servant living for God and others.
“Then your light shall break forth like the morning, your healing shall spring forth speedily, and your righteousness shall go before you; the glory of the Lord shall be your rear guard. Then you shall call, and the Lord will answer; you shall cry, and He will say, ‘Here I am’ (Isaiah 58:8-9).