Paul and Barnabas admonished the heathen to turn from “vanities unto the living God.” One cannot trust in the Lord and simultaneously trust in anything else. In order for an individual to be saved, he must repent of trusting in anything other than the Lord. One aspect of repentance involves ceasing to trust vanity and turning one’s faith toward the living and true God. This saving faith needs to become a living faith following salvation. Believers should consistently turn from “vain thoughts” and love the law of God (Psalm 119:113). They should turn from the vain labours that spend their strength for nought (Isaiah 49:4) and be “steadfast . . . in the work of the Lord” knowing that their “labour is not in vain in the Lord” (1 Corinthians 15:58). Additionally, believers should turn from “vain words” (Ephesians 5:6) and hold “forth the word of life” (Philippians 2:16).
Most Christians would consider biblical fasting a very unpleasant undertaking. Considering the complexities of the affliction offered by fasting might better help to understand its value. In our passage, the people of God determined to fast so that they might afflict themselves before the Lord. Several other passages discuss this affliction in even more detail. Isaiah 58:3 and 5 describes the affliction as not merely an affliction of the flesh, but also an affliction of the soul. Additionally, we learn that fasting humbles (Psalm 35:13) and chastens (Psalm 69:10) the soul. Fasting involves much more than merely opposition to one’s flesh. Fasting directly afflicts, chastens, and humbles the soul. Perhaps this is why it is so difficult to fast and so beneficial to do so.
Fasting, similar to other actions in life, has specific purposes and appointed times. The Bible offers various reasons why people might fast: an immediate need in prayer (2 Samuel 12:16), a need to loosen the bands of wickedness or undo heavy burdens (Isaiah 58:6), during times of elevated conflict or duty in service (Matthew 17:21; Acts 13:3), as a symbol of mourning (2 Samuel 1:12), and as an outward manifestation of true repentance (Jonah 3:5). This list is not exhaustive, but simply demonstrates that God’s people have many good reasons for fasting. Even if none of these circumstances surfaces in our lives, we should fast because we know that the Lord expects us to do so.