Question: "How is Jesus the 'True Shepherd' in John 10:1-5?"
Answer: By referring to Himself as the true Shepherd, Jesus was invoking imagery that would have been familiar to His hearers. He used the symbols of sheep and their shepherd several times, referring to Himself as not only the “True” Shepherd, but the Good Shepherd (John 10:11), and the Door of the sheep (John 10:7). The three declarations in John 10 present a complete picture of the Lord who is our Shepherd (Psalm 23).
In order to understand what Jesus intended to convey with sheep/shepherd imagery, we must understand the Middle Eastern shepherd of biblical times. His job was a dirty and dangerous one. Many times all the shepherd had to fight off lions and other wild animals was a staff with a crook. He willingly put his life on the line for his flock. At night, he would put the flock in a makeshift pen which had only one way in and out. The shepherd would open to door to the pen, call the sheep by name, and they would come in and settle safely for the night.
Sheep are skittish animals and "spook" easily. Because they knew the shepherd's voice, they would calm down and follow him and nobody but him. Several flocks can mix together, and when the flocks’ true shepherd speaks, they separate and follow him. If a thief comes the sheep will not follow him because they do not know his voice. At night the shepherd lies down at the gate to the pen, to give his life if necessary to protect his flock. And the thief can only climb in over the fence because the shepherd is guarding the gate. Jesus is the true Shepherd to the sheep (true believers) who are His. We know Him, we recognize His voice, and we follow only Him (John 10:27-28).
What Jesus is saying here ties right into John 14:6: "I am the way, the truth and the life. No one comes to the Father except by me." Jesus is not only the Good Shepherd who gives His life willingly for His sheep (John 10:11), but He is the also the "gate" or "door" of the sheep (John 10:9). The Greek word for door means literally a door or opening, but when used in a parable such as here it is a metaphor for one who gives salvation, who opens the door to heaven. So, Jesus is the true Shepherd who guards His sheep, the good Shepherd who gives His life for them, and the doorway to heaven for the sheep who know Him and are known by Him.
Jesus also says there were many who came before Him pretending to be good shepherds. But, He says, they are thieves and robbers who come in among the flock. He was alluding to the false shepherds of Israel, the Pharisees who did not love the people, nor were they willing to sacrifice for them. These self-appointed and self-righteous false shepherds led the sheep of Israel astray from the true knowledge of the Messiah, clinging to a works-based religion that could not lead to salvation (Ezekiel 34:1-31). These leaders were not the true shepherds of Israel, but were like thieves that plundered the flock for their own gain. Sadly, such false shepherds still abound today, more interested in fleecing the flock for their own personal gain, instead of feeding and protecting the sheep as true under-shepherds to the True Shepherd, the Lord Jesus Christ.