Prayer and Fasting - A Definition
Prayer and fasting is defined as voluntarily going without food in order to focus on prayer and fellowship with God. Prayer and fasting often go hand in hand, but this is not always the case. You can pray without fasting, and fast without prayer. It is when these two activities are combined and dedicated to God's glory that they reach their full effectiveness. Having a dedicated time of prayer and fasting is not a way of manipulating God into doing what you desire. Rather, it is simply forcing yourself to focus and rely on God for the strength, provision, and wisdom you need.
Prayer and Fasting - What the Bible Says
The Old Testament law specifically required prayer and fasting for only one occasion, which was the Day of Atonement. This custom became known as "the day of fasting" (Jeremiah 36:6) or "the Fast" (Acts 27:9). Moses fasted during the 40 days and 40 nights he was on Mount Sinai receiving the law from God (Exodus 34:28). King Jehoshaphat called for a fast in all Israel when they were about to be attacked by the Moabites and Ammonites (2 Chronicles 20:3). In response to Jonah's preaching, the men of Nineveh fasted and put on sackcloth (Jonah 3:5). Prayer and fasting was often done in times of distress or trouble. David fasted when he learned that Saul and Jonathan had been killed (2 Samuel 1:12). Nehemiah had a time of prayer and fasting upon learning that Jerusalem was still in ruins (Nehemiah 1:4). Darius, the king of Persia, fasted all night after he was forced to put Daniel in the den of lions (Daniel 6:18).

Prayer and fasting also occurs in the New Testament. Anna "worshipped night and day, fasting and praying" at the Temple (Luke 2:37). John the Baptist taught his disciples to fast (Mark 2:18). Jesus fasted for 40 days and 40 nights before His temptation by Satan (Matthew 4:2). The church of Antioch fasted (Acts 13:2) and sent Paul and Barnabas off on their first missionary journey (Acts 13:3). Paul and Barnabas spent time in prayer and fasting for the appointment of elders in the churches (Acts 14:23).
Prayer and Fasting - Required or Recommended?
The Word of God does not specifically command believers to spend time in prayer and fasting. At the same time, prayer and fasting is definitely something we should be doing. Far too often, though, the focus of prayer and fasting is on abstaining from food. Instead, the purpose of Christian fasting should be to take our eyes off the things of this world and focus our thoughts on God. Fasting should always be limited to a set time because not eating for extended periods can be damaging to the body. Fasting is not a method of punishing our bodies and it is not be used as a "dieting method" either. We are not to spend time in prayer and fasting in order to lose weight, but rather to gain a deeper fellowship with God.

By taking our eyes off the things of this world through prayer and biblical fasting, we can focus better on Christ. Matthew 6:16-18 declares, "When you fast, do not look somber as the hypocrites do, for they disfigure their faces to show men they are fasting. I tell you the truth, they have received their reward in full. But when you fast, put oil on your head and wash your face, so that it will not be obvious to men 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."
Prayer and Fasting - What Does it Accomplish?
Spending time in prayer and fasting is not automatically effective in accomplishing the desires of those who fast. Fasting or no fasting, God only promises to answer our prayers when we ask according to His will. 1 John 5:14-15 tells us, "This is the confidence we have in approaching God: that if we ask anything according to his will, he hears us. And if we know that he hears us - whatever we ask - we know that we have what we asked of him." In the prophet Isaiah's time, the people grumbled that they had fasted, yet God did not answer in the way they wanted (Isaiah 58:3-4). Isaiah responded by proclaiming that the external show of fasting and prayer, without the proper heart attitude, was futile (Isaiah 58:5-9).

How can you know if you are praying and fasting according to God's will? Are you praying and fasting for things that honor and glorify God? Does the Bible clearly reveal that it is God's will for you? If we are asking for something that is not honoring to God or not God's will for our lives, God will not give what we ask for, whether we fast or not. How can we know God's will? God promises to give us wisdom when we ask. James 1:5 tells us, "If any of you lacks wisdom, he should ask God, who gives generously to all without finding fault, and it will be given to him."