Jesus fasted before his public mission

Matthew 4, 1 – 11:

Then Jesus was led by the Spirit into the wilderness to be tempted by the devil. After fasting forty days and forty nights, he was hungry. The tempter came to him and said, “If you are the Son of God, tell these stones to become bread.” Jesus answered, “It is written: ‘Man shall not live on bread alone, but on every word that comes from the mouth of God.’” Then the devil took him to the holy city and had him stand on the highest point of the temple. “If you are the Son of God,” he said, “throw yourself down. For it is written:

“‘He will command his angels concerning you,

    and they will lift you up in their hands,

    so that you will not strike your foot against a stone.’”

Jesus answered him, “It is also written: ‘Do not put the Lord your God to the test.’”

Again, the devil took him to a very high mountain and showed him all the kingdoms of the world and their splendor. “All this I will give you,” he said, “if you will bow down and worship me.” Jesus said to him, “Away from me, Satan! For it is written: ‘Worship the Lord your God, and serve him only.’” Then the devil left him, and angels came and attended him.

A spiritual fast

Matthew 6, 16 – 18:

“When you fast, do not look somber as the hypocrites do, for they disfigure their faces to show others they are fasting. Truly I tell you, they have received their reward in full. But when you fast, put oil on your head and wash your face, so that it will not be obvious to others that you are fasting, but only to your Father, who is unseen; and your Father, who sees what is done in secret, will reward you.”

Acts 13, 2 – 3:

“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.” So after they had fasted and prayed, they placed their hands on them and sent them off.”

St. John Chrysostom - About fasting

"The fast quenches the frenzy of the body, defeats the inadequate lusts, cleanses and strengthens the soul, exalts it, and relieves it." (The Homily X on Creation ch. 1)

Father Dumitru Stăniloae - About the ascetic and post

"This heroic work of the will to purify and enlighten under the action of grace to prepare the human being to receive the deformed crown of holiness is called asceticism." (The Christian Ascetic and Mystic p 13)

"In reality, asceticism has a positive purpose, it seeks to fortify the flesh and release it from the worm of sin... It is true that the ultimate goal of asceticism is to release the nature not only from the movement of sinful desires, but also from the ideas of things that are revealed to the mind after purification of passions. But this only in order for the human being to gain independence from the created things, who through the passions enslaved the flesh, and that they should long for more eagerly after God. "(Idem 14)

"Fasting is at the same time a corporeal act and an act of deep spiritual character. It is a effort of will and a re-establishment of the reign of spirit on the body. In the Christian thinking, especially Orthodox, the soul and the body do not live their isolated lives, but they influence one another. As by the soul you can influence the body, so vice versa. A certain position and disposition of the body produces a certain state in the soul. The soul and body are as if they were in a circle, the influences pass from one to another. "(p 137)