We fast to focus on God.  When we do a fast, we don’t eat for twelve hours a day for three days.  While we fast, we pray and study the Bible.  God will show us revelation during the time of fast.  God shows favor in the things that we pray for.  When we fast, we do so in secret for God’s reward.

Jesus explains how to do fasting in Matthew chapter six verses sixteen through eighteen (NIV): 16 “When you fast, do not look somber as the hypocrites do, for they disfigure their faces to show others they are fasting. Truly I tell you, they have received their reward in full. 17 But when you fast, put oil on your head and wash your face, 18 so that it will not be obvious to others 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.

The way we treat our fellow man will represent God during our fast.  Isaiah fifty-eight verses six through twelve explain it like this: 

6 

“Is not this the kind of fasting I have chosen:

to loose the chains of injustice

    and untie the cords of the yoke,

to set the oppressed free

    and break every yoke?

7 

Is it not to share your food with the hungry

    and to provide the poor wanderer with shelter—

when you see the naked, to clothe them,

    and not to turn away from your own flesh and blood?

8 

Then your light will break forth like the dawn,

    and your healing will quickly appear;

then your righteousness[a] will go before you,

    and the glory of the Lord will be your rear guard.

9 

Then you will call, and the Lord will answer;

    you will cry for help, and he will say: Here am I.

“If you do away with the yoke of oppression,

    with the pointing finger and malicious talk,

10 

and if you spend yourselves in behalf of the hungry

    and satisfy the needs of the oppressed,

then your light will rise in the darkness,

    and your night will become like the noonday.

11 

The Lord will guide you always;

    he will satisfy your needs in a sun-scorched land

    and will strengthen your frame.

You will be like a well-watered garden,

    like a spring whose waters never fail.

12 

Your people will rebuild the ancient ruins

    and will raise up the age-old foundations;

you will be called Repairer of Broken Walls,

    Restorer of Streets with Dwellings.

There are other ways people do fasts: social media fasts, spending fasts, internet fasts, and intermittent fasts.  The Biblical way to fast is to refrain from food for three days.