“And the disciples of John and of the Pharisees used to fast: and they come and say unto him, Why do the disciples of John and of the Pharisees fast, but thy disciples fast not? And Jesus said unto them, Can the children of the bride chamber fast, while the bridegroom is with them? as long as they have the bridegroom with them, they cannot fast”. Mark 2:18–19
The connection between prayer and fasting is not specifically explained in Scripture, a common thread connecting the two runs through all the instances of prayer and fasting recorded in the Bible. In the Old Testament, fasting with prayer had to do with a sense of need and dependence, and/or of abject helplessness in the face of actual or anticipated calamity.
Prayer and fasting are combined in the Old Testament in times of mourning, repentance, and/or deep spiritual need.
Jesus explains in Marks account, that while He is physically with His disciples they have no need to fast as Jesus Himself is who they depend on, and while with Him they have no helplessness, no calamity, no deep spiritual need as He is the Son of God.
“And the same day, when the even was come, he saith unto them, Let us pass over unto the other side. And when they had sent away the multitude, they took him even as he was in the ship. And there were also with him other little ships. And there arose a great storm of wind, and the waves beat into the ship, so that it was now full. And he was in the hinder part of the ship, asleep on a pillow: and they awake him, and say unto him, Master, carest thou not that we perish? And he arose, and rebuked the wind, and said unto the sea, Peace, be still. And the wind ceased, and there was a great calm. And he said unto them, Why are ye so fearful? how is it that ye have no faith? And they feared exceedingly, and said one to another, What manner of man is this, that even the wind and the sea obey him?” Mark 4:35–41
In several instances in the Old Testament, fasting is linked with intercessory prayer. David prayed and fasted over his sick child (2 Samuel 12:16), weeping before the Lord in earnest intercession (vv. 21-22).
Esther urged Mordecai and the Jews to fast for her as she planned to appear before her husband the king (Esther 4:16). Fasting and petition are closely linked.
There are instances of prayer and fasting in the New Testament, but they are not connected with repentance or confession. The prophetess Anna “never left the temple but worshiped night and day, fasting and praying” Luke 2:37. At age 84, her prayer and fasting were part of her service to the Lord in His temple as she awaited the promised Savior of Israel.
Also in the New Testament, the church at Antioch was fasting in connection with their worship when the Holy Spirit spoke to them about commissioning Saul and Barnabas to the Lord’s work. At that point, they prayed and fasted, placed their hands on the two men and sent them off.
“Now there were in the church that was at Antioch certain prophets and teachers; as Barnabas, and Simeon that was called Niger, and Lucius of Cyrene, and Manaen, which had been brought up with Herod the tetrarch, and Saul. As they ministered to the Lord, and fasted, the Holy Ghost said, Separate me Barnabas and Saul for the work whereunto I have called them. And when they had fasted and prayed, and laid their hands on them, they sent them away”. Acts 13:1-3
NOTE: In all of scripture, this is the ONLY account where the Holy Spirit HIMSELF speaks directly, which is distinct from the Holy Spirit speaking through others.
In these examples, prayer and fasting are components of worshipping the Lord and seeking His favor. Nowhere, however, is there any indication that the Lord is more likely to answer prayers if they are accompanied by fasting. Rather, fasting along with prayer seems to indicate the sincerity of the people praying and the critical nature of the situations in which they find themselves. This speaks to the context of Jesus answer in Mark as fasting was unnecessary with His manifest presence.
For more context, the more critical the situation, the more appropriate fasting and prayer may be absent Jesus physical presence. In Mark 9, Jesus casts a demon from a boy. The disciples had been unable to perform the exorcism, although they had previously been given authority over unclean spirits (Mark 6:7). Later, the disciples asked Jesus why they failed in their attempts to free the boy from the demon, and Jesus said, “And he said unto them, This kind can come forth by nothing, but by prayer and fasting.” Mark 9:29. (also Matthew 17:21)
In this account Jesus adds the phrase “and fasting” in this particular case, the demon was exceptionally malicious and obdurate. “And he asked his father, How long is it ago since this came unto him? And he said, Of a child. And ofttimes it hath cast him into the fire, and into the waters, to destroy him: but if thou canst do any thing, have compassion on us, and help us”. Mark 9:21-22.
Jesus was saying that a determined spirt or demon, must be met with an equally determined faith. Prayer is a ready weapon in the spiritual battle and fasting helps to focus prayer and give it resolve.“Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints;” Ephesians 6:18
The theology of fasting is a theology of priorities in which believers are given the opportunity to express themselves in an undivided and intensive devotion to the Lord and to the concerns of spiritual life and warfare. This devotion is expressed by abstaining for a short while from such normal and good things as food and drink, so as to enjoy a time of uninterrupted communion with the Father.