Fasting was practiced by the Lord Himself. After prayer and fasting for forty
days in the wilderness, our Lord Jesus Christ victoriously faced the
temptations of the devil (Matthew 4:1-­11). The Lord himself asked the
disciples to use fasting as an important spiritual weapon to achieve spiritual
victories (Matthew 17:21; Mark 9:29; Luke 2:37). The example of the Lord was
followed by His disciples (Acts 14:23; 27:9; 1 Corinthians 7:5; 2 Corinthians 6:5,
11:27).
First of all, fasting is abstinence from food. By detaching us from earthly goods and realities,
fasting has a liberating effect on us and makes us worthy of the life of the spirit, a life similar to
that of angels.

Fasting is the advocate of repentance. Adam and Eve disobeyed God; they refused to fast from
the forbidden fruit. They became slaves of their own desires. But now through fasting, through
obedience to the rules of the Church regarding the use of spiritual and material goods, we may
return to the life in Paradise, a life of communion with God

Here are some of the verses regarding fasting:

Nehemiah 1:4 - When I heard these words I sat down and wept, and mourned for days; and I
continued fasting and praying before the God of heaven.

Matthew 6:16 - "And when you fast, do not look dismal, like the hypocrites, for they disfigure
their faces that their fasting may be seen by men. Truly, I say to you, they have received their
reward.

Matthew 6:18 - that your fasting may not be seen by men but by your Father who is in secret;
and your Father who sees in secret will reward you.

Mark 2:18 - Now John's disciples and the Pharisees were fasting; and people came and said to
him, "Why do John's disciples and the disciples of the Pharisees fast, but your disciples do not
fast?" And Jesus replied: "Can the wedding guests fast while the bridegroom is with them? As
long as they have the bridegroom with them, they cannot fast. The days will come, when the
bridegroom is taken away from them, and then they will fast in that day."

Acts 13:2 - While they were worshipping the Lord and fasting, the Holy Spirit said, "Set apart for
me Barnabas and Saul for the work to which I have called them."

Acts 13:3 - Then after fasting and praying they laid their hands on them and sent them off.
Fasting in the Orthodox Church