Matthew 17:19-21

19 Then came the disciples to Jesus apart, and said,
Why could not we cast him out?
20 And Jesus said unto them, Because of your
unbelief: for verily I say unto you, If ye have
faith as a grain of mustard seed, ye shall say unto
this mountain, Remove hence to yonder place; and it
shall remove; and nothing shall be impossible unto
you.
21 Howbeit this kind goeth not out but by prayer and
fasting.

In this particular case, the demon was exceptionally malicious and obdurate. Jesus seems to be saying that a determined foe 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.

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. This devotion will be 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 our Father. Our “confidence to enter the Most Holy Place by the blood of Jesus” (Hebrews 10:19), whether fasting or not fasting, is one of the most delightful parts of that “better thing” which is ours in Christ. Prayer and fasting should not be a burden or a duty, but rather a celebration of God's goodness and mercy to His children.

Physical Benefits of Fasting

• Lose weight and belly fat:

According to many studies, losing weight has shown to be possible and effective when fasting. Fasting allows the body to burn fat for energy when there is no sugar or food. Fasting can enhance hormone function to help with weight loss. Increased amounts of norepinephrine, lower insulin levels, and an increase of hormone levels all contribute to the breakdown of body fat. Multiple athletes fast to lose body fat percentage efficiently.

• Improves brain function and mental clarity:

Fasting has shown to improve brain performance because it boosts a protein called BDNF (brain- derived neurotrophic factor). BNDF activates the brain stem cells to convert into new neurons and stimulates other chemicals that promote neural health. Studies have also shown that it can increase the growth of new nerve cells, which could have benefits of brain functions.

• Improves insulin sensitivity/ lowering risk of type 2 diabetes:

Fasting has shown to have a positive effect on insulin resistance, enabling you to tolerate carbs better than normal. Fasting has been shown to have crucial benefits for insulin sensitivity and can lead to a reduction in blood sugar levels.

• May help prevent cancer:

There is some evidence on cancer patients, showing that fasting reduces various side effects of chemotherapy. Despite the fact there are human studies needed to be done, promising evidence from animal studies shows that fasting may help prevent cancer.

• May help you live longer:

Studies have shown how the lifespan of people in certain cultures increased due to their diets. Studies in rats have shown that fasting extends their lifespan. In some other studies, rats who have fasted lived 83% longer than rats who haven’t fasted.

• May be beneficial for your cardio health:

Heart disease is a worldwide killer. Fasting has shown to improve countless risk factors, such as blood pressure, LDL and total cholesterol, blood triglycerides and more.

• Can reduce oxidative stress and inflammation in the body:

Oxidative stress enhances aging and many chronic disease. Multiple studies show that fasting may enhance the body’s resistance to oxidative stress.

• Improves blood fat levels:

In 1997 the Annals of Nutrition Metabolism demonstrated that fasting lowered bad cholesterol, LDL, by 8 percent, triglycerides by 30%, and increase good cholesterol, HDL, by 14%. Fasting may be the perfect time to reprogram your body to get to eating healthy.

• Can help improve eating patterns:

With today’s food abundances, people have developed multiple eating disorders such as binge eating. Fasting all day and eating at a set time and allow yourself to eat appropriately.

• Can curb hunger:

Fasting helps regulate the hormones in your body so that you understand what true hunger is. Fasting can be like a reset button- the longer you fast, the more your body can regulate itself and correct hormones. It will also help you get full quicker.

I suggest water (and tea) only fasting for 5-6 days.

Reference
Reference

The Grim Reaper Preacher says, "Try reading the Bible from cover to cover - you'll like it."