"The one who enters by the gate is the shepherd of the sheep..." (John 10:1-5)

"Very truly I tell you Pharisees, anyone who does not enter the sheep pen by the gate, but climbs in by some other way, is a thief and a robber. The one who enters by the gate is the shepherd of the sheep. The gatekeeper opens the gate for him, and the sheep listen to his voice. He calls his own sheep by name and leads them out. When he has brought out all his own, he goes on ahead of them, and his sheep follow him because they know his voice. But they will never follow a stranger; in fact, they will run away from him because they do not recognize a stranger's voice." (John 10:1-5) 

What does this parable of the sheep mean?

Jesus is speaking directly to the Pharisees, who have assumed positions of leadership in the institutional temples of Jesus' time. They are assuming the role of teacher to those who attended these institutional temples.

The issue Jesus refers to regards entry into a relationship with God. Those who pretend to have a relationship with God but use their authority to abuse their followers are essentially trying to cheat their way in. They have not entered through the gate that was authorized by God.

The Pharisees' means of gaining entry is being compared to climbing in some other way. What is that? By establishing their authority through political appointment by the temple high priests.

This is being compared to cheating because this does not entail the hard work required to establish and maintain a loving service relationship with the Supreme Being, as Jesus and his disciples were doing.

This statement by Jesus also describes many others who assume the position of teacher due to being elected or appointed by a group of people or an individual. Whether it be an assembly of cardinals (e.g. pope), a council of deacons, or otherwise (e.g. priests or reverends). Such positions are elected or appointed political positions. Those positions are not empowered by the Supreme Being.

In Jesus' metaphor, those in these elected posts are gaining entrance into the sheep pen as a thief might. They are not being authorized and empowered by the Supreme Being, and thus they have no real ability to save people, as Jesus did.

Wasn't Jesus also a rabbi?

Yes, many greeted him as "rabbi" (teacher), and many accepted him as their spiritual teacher. Why?

Because they could see his real authority. They could understand that he could deliver his students and thus those who were serious about their spiritual lives followed him - the "sheep" in Jesus' metaphor.

And those who were not serious about their spiritual lives followed the ecclesiastical Pharisees and high priests of the institutional temple system. These are not the true "sheep" that Jesus is discussing here, because they are not serious about their spiritual lives.

Yet Jesus was not appointed or elected to any post.

But Jesus did accept baptism from John the Baptist. This means that Jesus did accept a teacher - though he didn't need to.

The teacher he accepted was not an elected official teacher. Rather, Jesus' teacher, John the Baptist, was empowered by the Supreme Being and had himself accepted a teacher within a long lineage of teachers that spanned back to David and Moses. None of these teachers were elected by an assembly of people or a council. Each simply accepted a teacher and God empowered them to teach.

Does God abide by the elections of men?

The Supreme Being does not accept or abide by the elections of men. The Supreme Being is supreme and He is not subject to the whims of people - even if those people are in the majority of a particular group or institution.

Elections of people are based on politics. This is not how God chooses and empowers His representative.

God's representative is empowered via the loving relationship that exists between His loving servant and Himself. He empowers those who have come to know Him and love Him in an intimate way. This relationship is not visible to those without spiritual vision and their own relationship with God. Jesus discussed this:
"You do not know me or my Father. If you knew me, you would know my Father also." (John 8:19)
and later,
"If God were your Father, you would love me, for I came from God and now am here. I have not come on my own; but He sent me." (John 8:42)
Jesus also explains the process of how God leads those who are truly seeking the truth to His representative:
"No one can come to me unless the Father Who sent me draws him..." (John 6:44)
A person who is sincere about finding God will find and recognize God’s messenger. How? Because God steers the sincere person to His representative and gives that person the vision to recognize His representative.

This doesn’t mean that everyone who hears God’s representative will recognize him as such. Those who don't recognize God's representative are not sincere about re-establishing their relationship with the Supreme Being.

Instead, they seek their personal agendas: they do not have open and humble minds that will hear from God’s representative. They think they know it all, and can sit in judgment of God's representative. This is precisely what the institutional temple priests and Pharisees were doing. They were envious of Jesus' authority and blinded by their own desires for authority and prestige.

The Supreme Being chooses His own representative and those who pretend to be without His authority can be compared to thieves. And those who are sincere about coming to know and love the Supreme Being will recognize and follow God's representative. This is the meaning of this parable by Jesus.