Jesus is instructing his students
Remember that Jesus is speaking here to his disciples (Looking at his disciples, he said:... (Luke 6:20)).
We can thus understand that Jesus is giving his students instruction. He is instructing them on how to conduct themselves and how to progress in their spiritual advancement.
This lies contrary to those who will attempt to apply Jesus' statements here and elsewhere out of context, and many who preach the ultimate contradiction of teaching that Jesus is the only teacher. They are teaching us this. Why do we need them to teach us this if Jesus is the only teacher? Why do they teach - preach - at all if Jesus is the only teacher?
Teaching that Jesus is the only teacher is hypocritical
It is quite simply hypocritical to be teaching that we only need to accept Jesus as our teacher.
Worse, sectarian teachers and other speculative interpreters of the Bible like to stretch and twist Jesus' various statements, often out of their original context. They will attempt to use Jesus' statements to apply to situations they were not originally intended to be applied to. This is called speculative interpretation, and sectarian institutions are now flooded with so many different speculative interpretations of the Bible and Jesus' teachings.
And this is precisely why Jesus is underscoring here the need to be "fully trained" by "his teacher."
Having a living teacher who has been trained by a teacher will be able to train us in the same way they were trained, yet still apply those teachings to the present time and circumstances. We can see by Jesus' instruction to his students is so important:
"Can a blind man lead a blind man?"
Who the pastor or priest of that church is often a secondary consideration. As explained by Jesus, this is a mistake.
There is a frequent assumption that anyone who has been ordained by educators approved by a church's leaders is qualified to be our teacher. This is seemingly verified by a local church committee, who will often select the pastor to be their church teacher.
The Catholic church process is a bit different, with priests being appointed by regional bishops who govern that territory on behalf of the Catholic diocese.
Both processes are essentially the same. The pastor or priest first must attend a seminary college and receive a degree in divinity, and then must be qualified through testing and sometimes interview to become ordained. Then the person is selected through either a committee of deacons or a bishop to be the teacher of a particular church and those who attend that church.
This process - of election or appointment of teachers through a political process by other people - is called an ecclesiastic process. It is ecclesiastical because people are appointing the teacher. The decision is being made by committees of people. This makes the selection process a political process, where candidates are interviewed and selected by elections of people. The pope is also a politically-elected teacher.
This opposes the process Jesus is teaching:
"everyone who is fully trained will be like his teacher."
This means that every person who is fully trained by a bona fide teacher is equipped to represent the teacher and the teachings of the teacher. There is no official certification by any institution of men required.
But what does "fully trained" mean? It means that the person has become committed to the teachings of their teacher. Being "fully trained" means they are living those teachings. This means they have become devoted to those teachings.
Many will say that the priest or pastor is being fully trained in seminary school. This may be the case, but only if the seminary school teacher has themselves taken on a teacher who is qualified to give them spiritual training.
The problem is that most of the seminary colleges are professional institutions. They are not staffed by those who are carrying out Jesus' instruction to serve the Supreme Being. They are staffed by those who are being paid a salary to teach. This means they are professional teachers - not spiritual teachers.
As clearly stated by Jesus above, a teacher is only qualified if they are first "fully trained" by a "fully trained" spiritual teacher. And because Jesus' teachings taught service ("the will of my Father"), they must be serving the Supreme Being with that service of teaching. If they are receiving a salary in exchange for their teachings, then it is not service. It is business.
Those pastors or priests who were students of these professional teachers carry on that tradition by receiving salaries for their teaching in churches. This receiving of a salary disqualifies them from being a bona fide spiritual teacher, however, because they are not conducting service to God: They are conducting business masquerading as service.
Thus what we see in sectarian institutions today is precisely what Jesus warned his students of:
"Can a blind man lead a blind man?"
A person who is maintaining a business relationship with God - conducting service in return for a salary or some other reward - can only train us to do the same. They cannot train us to become loving servants of the Supreme Being.
They also cannot teach us the answers to the central questions about life: Who am I? Why am I here? Why is there so much suffering here? and Who is God?
And it is for this reason that so many students of these professional Church teachers focus their attention not on regaining their natural position as one of God's loving servants, but they focus upon praying to God for stuff.
This is why so many sectarians will pray to win football games, pray to get a raise, pray for their leg to get better and so on. We see football stars praying and making their crosses at the games, and we see Olympic competitors all praying before their race, game or match.
What are they praying for? They are praying to win. They are praying for fame. They are praying for wealth. They are praying for health.
What kind of a relationship with God is this? This is a relationship where we expect God to serve us: We expect Him to help us win the race, fix our leg, make us wealthy and so on.
What does this have to do with loving service? With devotion? Nothing. It is a business relationship.
And it is this very business relationship that makes so many people walk away from their faith in the Supreme Being. They didn't get what they wanted, so to heck with God. Why pray if we don't get what we want?
This type of relationship is specifically the result of the 'blind leading the blind' as Jesus states here. Those professional teachers who are conducting business relationships with God are leading others into that same blindness.
What are they blind to?
They are blind to our identity as spiritual and not the temporary physical body. They are blind to why we are here in the physical world first place. They are blind to our original relationship of loving service to the Supreme Being - a relationship that ultimately brings us happiness.
They are blind to the complete fulfillment that comes as a result of engaging in devotional service to the Supreme Being without any expectation of reward.
They are blind to these because they do not know about these. They have not been "fully trained."
This is because loving service to the Supreme Being without any expectation of reward requires love. It requires a person to love God. And how does a person learn to love God?
First they need to be introduced to God - the Person God. We cannot love someone we do not know.
This introduction must come from a person who already knows the Supreme Being. Only a person who knows God can introduce us to Him. This is not only God's requirement: It is the universal law of relationships.
Just imagine if we told someone that we were going to introduce them to the President. So they get all excited, and when the day comes, they find out we don't really know the President. We just pretended to know him. Can that person come to know the President without being introduced by someone who already knows him? Likely not. Like most people, the President will typically only trust a person if they are introduced by someone they already trust.
While the Supreme Being knows us all, He still maintains this sort of process of introduction because God is a relationship person. Relationships are important to Him because love requires a relationship, and the process is more for us than Him - we are the ones who need to understand our relationship with God. So God has put in place a process whereby a person must come into contact with, and learn from someone who already has a relationship with Him before they can be re-introduced to Him. This, of course, requires having a relationship with that teacher.
This is important for a myriad of reasons, but one of the most important is the fact that when we learn about God from someone who has a relationship with God, we come to know God: we come to understand what pleases God.
Let's say that a friend who really knew the President wants to introduce us. He will likely tell us that, for example, the President likes to play basketball. So our friend might suggest we bring our basketball shoes and be ready for a game of hoops. The President will most certainly be pleased when we come to visit with a basketball, wearing basketball shoes. This will make the process of establishing our own relationship with the President that much easier.
It is similar with God, because a fully trained teacher will show us how we can apply our lives at this very point in time and space in such a way that will please the Supreme Being. Should we truly want to come to know God we will follow those instructions.
And when the Supreme Being sees this, He is pleased. He is pleased because we are committing ourselves in such a way that is pleasing to Him.
This is not only illustrated by this statement above by Jesus. It is also illustrated as Jesus approached and was baptized by John the Baptist. John knew that Jesus was an exalted lover of God already: But he still accepted Jesus as his student by baptizing him. Jesus even commented on the necessity of this process:
Then Jesus came from Galilee to the Jordan to be baptized by John. But John tried to deter him, saying, "I need to be baptized by you, and do you come to me?" Jesus replied, "Let it be so now; it is proper for us to do this to fulfill all righteousness." (John 3:13-15)This is not about getting stuff from God. It is not about God fixing our leg, making us wealthy or helping us win the game. Love for God has not about God serving us: It is about us serving God. "To fulfill all righteousness" in this context means to conduct oneself in such a way pleasing to God.
This is confirmed by the Greek word δικαιοσύνη (dikaiosynē) translated to "righteousness." This word means "integrity, virtue, purity of life, rightness, correctness of thinking feeling, and acting;" and in this application, "the condition acceptable to God." Being acceptable to God means pleasing God. Jesus wanted to please God with his becoming one of John's students - the meaning of baptism.
Just imagine if we were to approach a person we wanted to become friends with, and all we did is ask him to do stuff for us. Would that make for a healthy relationship? The other person would likely dismiss us - as it would be easy to see that we were simply interested in using them to get what we wanted. We were not interested in having a relationship with them.
You see, the Supreme Being is a person. He enjoys loving relationships. He does like to do things for those He loves - and He is doing things for us all the time regardless of our appreciation of them. But a true loving relationship is about service. A person who truly loves another will want to do what pleases that person.
This is what Jesus was trying to teach his students: About loving God and serving God. One does not exist without the other.
This is confirmed by Jesus' most important instruction, which had been passed down from one "fully trained" teacher to another over many centuries, as evidenced by Moses teaching the same instruction to his own students:
"'Love the Lord your God with all your heart and with all your soul and with all your strength and with all your mind'" (Luke 10:27 and Deuteronomy 6:5)