And it came to pass in those days, that Jesus came from Nazareth of Galilee, and was baptized of John in Jordan. And straightway coming up out of the water, he saw the heavens opened, and the Spirit like a dove descending upon him: And there came a voice from heaven, saying, Thou art my beloved Son, in whom I am well pleased.
And immediately the spirit driveth him into the wilderness. And he was there in the wilderness forty days, tempted of Satan; and was with the wild beasts; and the angels ministered unto him.
Now after that John was put in prison, Jesus came into Galilee, preaching the gospel of the kingdom of God, And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel. (Mark 1:9-15 KJV)
O LORD, who for our sake didst fast forty days and forty nights; Give us grace to use such abstinence, that, our flesh being subdued to the Spirit, we may ever obey thy godly motions in righteousness, and true holiness, to thy honour and glory, who livest and reignest with the Father and the Holy Ghost, one God, world without end. Amen. (from the 1928 Book of Common Prayer)
The picture above is of Christ in the Desert by Ivan Kramskoi.