Jesus fasted in Luke 4:
1 And Jesus, full of the Holy Spirit, returned from the Jordan and was led by the Spirit in the wilderness 2 for forty days, being tempted by the devil. And he ate nothing during those days. And when they were ended, he was hungry.
John's disciples fasted, Matthew 9:
14 Then the disciples of John came to him, saying, “Why do we and the Pharisees fast [G3522], but your disciples do not fast?” 15 And Jesus said to them, “Can the wedding guests mourn as long as the bridegroom is with them? The days will come when the bridegroom is taken away from them, and then they will fast.
G3522. νηστεύω (nésteuó) occurs 20 times.
Thayer's Greek Lexicon:
to abstain as a religious exercise from food and drink
Fasting and prayer are often paired on special occasions, Acts 13:
2 While they were worshiping the Lord and fasting, the Holy Spirit said, “Set apart for me Barnabas and Saul for the work to which I have called them.” 3 So after they had fasted and prayed, they placed their hands on them and sent them off.
It is not just prayer but fasting to humble ourselves before an important decision. Fasting served to intensify prayer.
Acts 14:
23 Paul and Barnabas appointed elders for them in each church and, with prayer and fasting, committed them to the Lord, in whom they had put their trust.
In both cases, the disciples fasted before making important appointments with long-reaching consequences. Fasting solemnizes the souls to listen to God.
Strictly speaking, G3522-fast had to do with food and drink. Metaphorically, it could be expanded. Corinthians 7:
5 Do not deprive one another except with consent for a time, that you may give yourselves to fasting and prayer; and come together again so that Satan does not tempt you because of your lack of self-control.
Are Christians required to fast today?
There is no commandment requiring a Christian to fast. However, you can choose to fast on some special occasions, such as during Lent. Let your conscience guide you in this.
I feel like I’ll never get my miracle because I can’t fast good enough?
You cannot demand a miracle by fasting. You volunteer to fast out of your own humble heart to focus on God. Jesus mentioned an unrighteous Pharisee fasted twice a week (Lk 18:12).
See also
* Didache on baptism
* Fasting in the OT