Fasting is not some kind of bargaining chip by which we say to God,
if I fast, then you do this for me. If I go without peanut butter and chocolate ice-cream, then you will bless this.That is not what fasting is about. Now, some people use fasting like this, and that is a terrible sin that is decried in the prophets. Thinking that somehow you can obligate God by fasting. In fact, in Isaiah 58:1–14, God says to his people,instead of you fasting, I would much rather you would be fair with your employees, take care of the hungry, and clothe the naked. Your fasting stinks, because by it, you are thinking of obligating me to bless you. That is not how it works.What is fasting? Fasting is obviously abstaining from something and most typically it is food…So why do we fast? Well, at the heart of fasting is actually nothing less than an expression of our desire for God above everything else—even our daily food—and our dependence upon God in all things. So that is what fasting does. In fasting we say, in a sense, we are going to go without food so that we can demonstrate our hunger for God. I am going to go without food as an expression of my utter need for the Lord, my utter dependence upon God. It is no accident, by the way, that fasting is always connected with prayer. In the time that you would normally spend eating and feeding your body, you are expressing your dependence upon God in prayer and seeking your Father's face.1
Brian Borgman
21 Then I proclaimed a fast there, at the river Ahava, that we might humble ourselves before our God, to seek from him a safe journey for ourselves, our children, and all our goods.