Is fasting really necessary for the believers?

 Matthew 9:15  And Jesus said unto them, Can the children of the bridechamber mourn, as long as the bridegroom is with them? but the days will come, when the bridegroom shall be taken from them, and then shall they fast.

As food is meant for the body, fasting and prayer is for the growth of the spirit. 

As a born again Christian, it is a must for you to fast and to pray often. Both fasting and praying are ways of exercising ones spirit, as we all know that God is Spirit and those who worship God must worship in the spirit. If your spiritual antenna is weak you may not be able to pick things in the spirit. Studying and meditating on the words of God is important but it is impossible for an eagle to fly with a wing; you can't fast and pray and neglect the ministry of the words of God, and you can't give yourself to teaching and studying the word of God and neglect fasting and prayer.

If you really want to grow spiritually, you must exercise your spirit.

Without fasting and prayer there are some assignments of the kingdom that you may not be able to carry-out.

So also, without the truth, which is the word of God; one may fast into error and one may pray into error if the truth is not abide in him.

If you want to fulfill purpose, you must fast. Queen Esther was able to break kings protocol when she engaged in fasting and prayer. "Esther 4:1-17"

It is a must for every believers to fast, to pray, and to meditate on the words of God.

"God is spirit, and those who worship God must be led by the Spirit to worship him according to the truth." John 4:24