“And I tell you, every one who acknowledges me before men, the Son of man also will acknowledge before the angels of God; but he who denies me before men will be denied before the angels of God. (Luke 12:8-9)
And brought them out and said, “Men, what must I do to be saved?” And they said, “Believe in the Lord Jesus, and you will be saved, you and your household.” (Acts 16:30-31)
Moses writes that the man who practices the righteousness which is based on the law shall live by it. But the righteousness based on faith says, Do not say in your heart, “Who will ascend into heaven?” (that is, to bring Christ down or “Who will descend into the abyss?” (that is, to bring Christ up from the dead). But what does it say? The word is near you, on your lips and in your heart (that is, the word of faith which we preach); because, if you confess with your lips that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved. For man believes with his heart and so is justified, and he confesses with his lips and so is saved. The scripture says, “No one who believes in him will be put to shame.” For there is no distinction between Jew and Greek; the same Lord is Lord of all and bestows his riches upon all who call upon him. For, “every one who calls upon the name of the Lord will be saved.” (Romans 10:5-13)
When you are fasting unto the Lord Jesus you might be doing it to spend with him. You might want to get closer to him. Sometimes fasting is just so that you want to be undisturbed by the needs of the flesh so that you can concentrate on the Living God our Father. There’s always a good reason to fast. The Holy Spirit may lead you to fast and pray or sometimes require you to only pray without fasting. Listen to him and discern.
Never fast out of legalism or trying to earn salvation or forgiveness of sins for it won’t actually save you. Only the Lord Jesus Christ can save you from your sins. Fasting therefore must be done without guile and hypocrisy.
In Isaiah chapter 58, the Lord God condemns unworthy fasting but also sets the precedent on what fasting is considered pure. Lets read the following:
58 “Cry aloud; do not hold back;
lift up your voice like a trumpet;
declare to my people their transgression,
to the house of Jacob their sins.
2 Yet they seek me daily
and delight to know my ways,
as if they were a nation that did righteousness
and did not forsake the judgment of their God;
they ask of me righteous judgments;
they delight to draw near to God.
3 ‘Why have we fasted, and you see it not?
Why have we humbled ourselves, and you take no knowledge of it?’
Behold, in the day of your fast you seek your own pleasure,
and oppress all your workers.
4 Behold, you fast only to quarrel and to fight
and to hit with a wicked fist.
Fasting like yours this day
will not make your voice to be heard on high.
5 Is such the fast that I choose,
a day for a person to humble himself?
Is it to bow down his head like a reed,
and to spread sackcloth and ashes under him?
Will you call this a fast,
and a day acceptable to the Lord?
6 “Is not this the fast that I choose:
to loose the bonds of wickedness,
to undo the straps of the yoke,
to let the oppressed go free,
and to break every yoke?
7 Is it not to share your bread with the hungry
and bring the homeless poor into your house;
when you see the naked, to cover him,
and not to hide yourself from your own flesh?
8 Then shall your light break forth like the dawn,
and your healing shall spring up speedily;
your righteousness shall go before you;
the glory of the Lord shall be your rear guard.
9 Then you shall call, and the Lord will answer;
you shall cry, and he will say, ‘Here I am.’
If you take away the yoke from your midst,
the pointing of the finger, and speaking wickedness,
10 if you pour yourself out for the hungry
and satisfy the desire of the afflicted,
then shall your light rise in the darkness
and your gloom be as the noonday.
11 And the Lord will guide you continually
and satisfy your desire in scorched places
and make your bones strong;
and you shall be like a watered garden,
like a spring of water,
whose waters do not fail.
12 And your ancient ruins shall be rebuilt;
you shall raise up the foundations of many generations;
you shall be called the repairer of the breach,
the restorer of streets to dwell in.
Jesus himself did not do away with fasting. In fact he set the standard for all of us who believe in him in Matthew 6:16-18
16 “And when you fast, do not look gloomy like the hypocrites, for they disfigure their faces that their fasting may be seen by others. Truly, I say to you, they have received their reward. 17 But when you fast, anoint your head and wash your face, 18 that your fasting may not be seen by others but by your Father who is in secret. And your Father who sees in secret will reward you.