Go, gather together all the Jews who are in Susa, and fast for me. Do not eat or drink for three days, night or day. I and my mates will fast as you do. When this is done, I will go to the king, even though it is against the law. And if I perish, I perish. Esther 4:16
Fasting is a lost discipline in the church today and this partly explains why the church is powerless and scrambles for human recipes to resolve issues that God is waiting to take care of for us. Many who fast today do the ‘convenient’ fast which does not stir our souls at all. We snack and drink and do not feel the hunger or thirst that is supposed to redirect our souls to the spiritual food and drink we really need.
The imminent extermination of the Jews in the Persian kingdom was enough to take away any appetite for food, drink, sleep, work, entertainment, etc. for days. So, when Esther called for a 3-day and night fast, it was just natural. Christians that are confronted with Islamist terrorism, oppressive governments, natural disasters, etc. go into such fasting all the time.
The West is in a spiritual comatose while holding to life support as an option rather than turning to God in fasting and prayer. We do not want to give up our comfort.
The reason why our prayers are more effective when we fast is because it helps us to humble ourselves before God. We quieten ourselves and listen more to God. Our motives are exposed, and we are more willing to align ourselves with God’s will than our desires.
God does not reveal His supernatural power to people who come to prayer in hurry and leave in hurry. Therefore, we individually need at least a whole day in a week or month to have uninterrupted time with God alone in fasting and prayer.