Jesus is My Good Shepherd

When God told Moses he was about to die, Moses cried out to the LORD, asking that He would provide a leader for His people, so that they would not be like shepherdless sheep.
Numbers 27:15-17
Moses said to the LORD, "May the LORD, the God of the spirits of all mankind, appoint a man over this community to go out and come in before them, one who will lead them out and bring them in, so the LORD's people will not be like sheep without a shepherd."
Moses did not know when God provided Joshua, son of Nun, to be the judge over the people of Israel as they entered the Promised Land without him, that God would later live among His people Himself, shepherding the flock that is the people of God with His own hand. This Good Shepherd is Jesus, God's one and only Son.

But first, God's people were to suffer under many godless leaders, who did not shepherd the people according to God's will.
Zechariah10:2
The idols speak deceit, diviners see visions that lie; they tell dreams that are false, they give comfort in vain. Therefore the people wander like sheep oppressed for lack of a shepherd.

It was at this time that God promised He Himself would tend His sheep, the people of God.
Ezekiel 34:11-12,15-16
" 'For this is what the Sovereign LORD says: I myself will search for my sheep and look after them. As a shepherd looks after his scattered flock when he is with them, so will I look after my sheep. I will rescue them from all the places where they were scattered on a day of clouds and darkness. … I myself will tend my sheep and have them lie down, declares the Sovereign LORD. I will search for the lost and bring back the strays. I will bind up the injured and strengthen the weak, but the sleek and the strong I will destroy. I will shepherd the flock with justice.

God promised that when He shepherded His people, they would know HIm and recognise Him, in a way that His faithless people had not before.
Ezekiel 34:30-31
Then they will know that I, the LORD their God, am with them and that they, the house of Israel, are my people, declares the Sovereign LORD. You my sheep, the sheep of my pasture, are people, and I am your God, declares the Sovereign LORD.' "

Up until the time of Jesus' ministry, the Jews were indeed like sheep without a shepherd.
Mark 6:34
When Jesus landed and saw a large crowd, he had compassion on them, because they were like sheep without a shepherd. So he began teaching them many things.

Jesus lived with them and taught them. Jesus Christ is the promised Good Shepherd.
John 10:11
"I am the good shepherd. The good shepherd lays down his life for the sheep. …

Long ago, God had also promised that He would strike His own promised Shepherd!
Zechariah 13:7,9
"Awake, O sword, against my shepherd, against the man who is close to me!" declares the LORD Almighty. "Strike the shepherd, and the sheep will be scattered, and I will turn my hand against the little ones. ...
This third I will bring into the fire; I will refine them like silver and test them like gold. 
They will call on my name 
and I will answer them; I will say, 'They are my people,' and they will say, 'The LORD is our God.' "

Jesus suffered on the cross, in fulfilment of this prophecy. His death achieved salvation to the Jews who believed in Him, but also for others, Gentiles (non-Jews like myself) who believed in Him. All believers - Christians - are now members of one flock, the Church Universal, under our Good Shepherd Jesus Christ.
John 10:14-16
"I am the good shepherd; I know my sheep and my sheep know me— just as the Father knows me and I know the Father—and I lay down my life for the sheep. I have other sheep that are not of this sheep pen. I must bring them also. They too will listen to my voice, and there shall be one flock and one shepherd.”

Jesus prophesied of himself that after He, the Shepherd, was struck, he would rise again.
Matthew 26:31
Then Jesus told them, "This very night you will all fall away on account of me, for it is written: " 'I will strike the shepherd, and the sheep of the flock will be scattered.' But after I have risen, I will go ahead of you into Galilee."

Before he died, Jesus taught and healed the people, leading them as a shepherd leads and guides his sheep. But He knew that once He died, rose and ascended to heaven, the people would need under-shepherds ("overseers"), who followed Jesus in leading the people to follow Jesus also. So he taught His Twelve disciples.
Matthew 9:35-38
Jesus went through all the towns and villages, teaching in their synagogues, preaching the good news of the kingdom and healing every disease and sickness. When he saw the crowds, he had compassion on them, because they were harassed and helpless, like sheep without a shepherd. Then he said to his disciples, "The harvest is plentiful but the workers are few. Ask the Lord of the harvest, therefore, to send out workers into his harvest field."

Paul told the Ephesian elders, leaders of the church in Ephesus, how to guide and lead Christians. He warned them that there would be wrong teachers and others who would try to attack the church as a whole or Christians individually. We must still(!) be on our guard against those who will "distort the truth" in order to draw people away from the saving truth of the knowlege of our Good Shepherd, Jesus Christ.
Acts 20:28-31a
Keep watch over yourselves and all the flock of which the Holy Spirit has made you overseers. Be shepherds of the church of God, which he bought with his own blood. I know that after I leave, savage wolves will come in among you and will not spare the flock. Even from your own number men will arise and distort the truth in order to draw away disciples after them. So be on your guard! ...

Peter also instructed the elders to oversee the church, and he told them their motivation should be to serve the people and so serve the "Chief Shepherd".
1 Peter 5:1-4
To the elders among you, I appeal as a fellow elder, a witness of Christ's sufferings and one who also will share in the glory to be revealed: Be shepherds of God's flock that is under your care, serving as overseers—not because you must, but because you are willing, as God wants you to be; not greedy for money, but eager to serve; not lording it over those entrusted to you, but being examples to the flock. And when the Chief Shepherd appears, you will receive the crown of glory that will never fade away.

What a promise! Yet it comes with a warning:
Matthew 25:31-34,41,46
"When the Son of Man comes in his glory, and all the angels with him, he will sit on his throne in heavenly glory. All the nations will be gathered before him, and he will separate the people one from another as a shepherd separates the sheep from the goats. He will put the sheep on his right and the goats on his left.
"Then the King will say to those on his right, 'Come, you who are blessed by my Father; take your inheritance, the kingdom prepared for you since the creation of the world. …
"Then he will say to those on his left, 'Depart from me, you who are cursed, into the eternal fire prepared for the devil and his angels. …
"Then they will go away to eternal punishment, but the righteous to eternal life."

Before the Day when the Son of Man comes in His glory, we are charged with doing the LORD's will, which we can only do through His strength and by His enabling. And so I pray:
Hebrews 13:20-21
May the God of peace, who through the blood of the eternal covenant brought back from the dead our Lord Jesus, that great Shepherd of the sheep, equip you with everything good for doing his will, and may he work in us what is pleasing to him, through Jesus Christ, to whom be glory for ever and ever. Amen.

Aah... the glory of the gospel!
1 Peter 2:21b-25
… Christ suffered for you, leaving you an example, that you should follow in his steps. 
 "He committed no sin, 
and no deceit was found in his mouth." When they hurled their insults at him, he did not retaliate; when he suffered, he made no threats. Instead, he entrusted himself to him who judges justly. He himself bore our sins in his body on the tree, so that we might die to sins and live for righteousness; by his wounds you have been healed. For you were like sheep going astray, but now you have returned to the Shepherd and Overseer of your souls.