According to how I am reading John's gospel, darkness is the lie that the spirit goes from teacher to student, such that a good teacher carefully selects and instructs students worthy of carrying his lessons to fruition.
I believe that the darkness is the spiritual darkness that permeates a world where the devil rules as king. (1 John 5:19) There is no part of this world that the devil does not control. His stamp is on everything.....corrupt politics, greedy commercialism and false religion. The light that Jesus brings dispels that darkness but only for those who accept him for who he is.....and he is not God....but sent by God to penetrate the darkness.....to reveal the truth and to save those who have not been taken in by satan's deceptions. The trinity muddies the waters and confuses God's true identity....which the Jews knew to be one God, not three occupying the same head.
In this situation the breath of the teacher becomes the breath of the student, so the spirit's trajectory is thought to be controlled and sustained by the teacher student relationship. John the Baptist departs from that teaching.
I have no idea where your reasoning comes from.....I do not see this in John’s gospel.
John the Baptist was the one sent ahead in advance of the Messiah to "prepare the way", so that the people were in the right frame of mind and heart to receive him.....and to repentant, publicly demonstrated by their baptism.
John’s Baptism did not make Jews into Christians however, but prepared their hearts for Jesus’ teachings. Those baptized by John had to undergo Christian baptism as they chose to become Christ’s disciples.
Here in John's gospel is John the Baptist preaching about it as if to Jews since there are no gentiles in the story.
Jesus was sent only to
“the lost sheep of the house of Israel”.....he was not sent to the Jewish religious leaders because they were already set in their traditions and would not budge from them. He castigated them at every opportunity. (Matthew 23) But because of God's promise to Abraham, the Jews had first option to come into “the new covenant” and rule with Christ in his Kingdom.....to become "a kingdom of priests and a holy nation". (Exodus 19:4-6)
When the Jews rejected Jesus as Messiah and had him put to death, (innocent of all charges against him) only after that, when Israel did to Jesus what they had done to all the other prophets, (Matthew 23:37-39) was God’s attention finally turned to the Gentiles to take out of them
“a people for his name”. (Acts 15:14)
Paul called those Christians, both Jewish and Gentile
“the Israel of God”. (Galatians 6:16) This was no longer fleshly Israel, but spiritual Israel. God had done what John the Baptist had said he would do. (Matthew 3:7-8) He can raise up children for Abraham even from the stones.
How to reconcile this teaching to the fact that there are teachers among Christians and in Paul's letters? It may sound interesting but is a side topic. The spirit is not controlled, not pinned down. Like the tabernacle follows the glory, the teachers must follow the spirit. The spirit doesn't follow the teachers, so having the right teacher doesn't guarantee anything.
That was not true in Jesus’ case. He was the only teacher who could give the power of the Holy Spirit to his disciples....first by the mention of his name, and after his death and resurrection, by the power he sent to his disciples so that many more would come out of corrupted worship and become footstep followers of Christ....both Jews and Gentiles. Those spirit anointed teachers made it their life's work to find more disciples for Christ as Jesus had instructed them to do. (Matthew 28:19-20)
There is no pedigree or school of the prophets. John is I think saying that the time of Jeremiah 31:34 has come, that Jesus birth heralds a new time. Therefore John says the light dispels the old thinking, and it marks those who resist as part of the unformed world that is being replaced by creation.
John heralded the arrival of the Messiah. But John died before Jesus did, so he was not aware that Jesus was executed. He was a man born to be a prophet and he did his job well but he was anointed with God's spirit from birth.
It was Jesus’ apostles who carried on his work and demonstrated the power of God’s spirit in their activities. That was not to be manifest past the apostolic period however. The gifts of the spirit died with the apostles because seeing miracles, Paul said, was the trait of a spiritual infant.....they needed to grow up and take on the task as mature Christians of preaching and teaching "to the most distant part of the earth".
The result goes far beyond teachers because ultimately this is about the large numbers of gentiles who become disciples, catholics, gnostics and various other varieties many of which we no longer know about.
The corruption foretold for Christianity is seen clearly in history....as soon as that corruption and bloodshed entered the Church, Christ left the building. What gained ascendancy was an imitation Christianity....the "weeds" of Jesus parable. (Matthew 13:24-30; 36-43; Matthew 7:21-23) Planted by the devil in the ultimate deception, they betray their true character by being 'part of the world' and forming friendships and alliances with worldly nations and participating in their political wars. (John 15:18-21; James 4:4, Matthew 5:43-45)
What masquerades as Christianity today is a mish-mash of human traditions, opinions and mistranslated Bible verses.
Christ's true followers would all speak in agreement and hold to the same truth. (1 Corinthians 1:10) They will not have blood on their hands....and then wonder why their prayers are not answered.....(Isaiah 1:15)