There is an example in the Bible where an Ethiopian convert to Judaism was riding along in a chariot, reading aloud a prophesy in Isaiah. A Christian evangelizer, Phillip was directed to approach him and ask a question....
“Do you actually know what you are reading?”...to which the man replied.....
“Really, how could I ever do so unless someone guided me?” So he urged Philip to get on and sit down with him." (Acts 8:26-39)
For the same reason that Jesus sent his disciples out to preach, we need someone to explain the scriptures to us.
Given that the Jews were already well versed in their scriptures, why did they need to be guided about what to believe? Their leaders had corrupted God's word by adding so many traditions and meaningless rituals to what God had commanded, that the average person found them impossible to keep, and just gave up trying....these became
"the lost sheep of the house of Israel", (Matthew 15:24) that Jesus was sent to. He was not sent to the Pharisees because these wicked men had no interest in the truth, only in their position and entitlements. Jesus knew that they were incorrigible. (Matthew 23:37-39)
Jesus said of those men...
“Woe to you, scribes and Pharisees, hypocrites! because you shut up the kingdom of the heavens before men; for you yourselves do not go in, neither do you permit those on their way in to go in.
“Woe to you, scribes and Pharisees, hypocrites! because you traverse sea and dry land to make one proselyte, and when he becomes one you make him a subject for Ge·henʹna twice as much so as yourselves." (Matthew 23:13-36)
The very same processes that corrupted Judaism have also corrupted Christendom. It was foretold that this apostasy would occur by Jesus and his apostles. (Matthew 13:24-30; 1 Timothy 4:1; 2 Thessalonians 2:3; Acts 20:30; 2 Peter 2:1)
If you learned your "Christianity" from Christendom's church system, then you did not learn the teachings of Christ, just as the first century Jews were not learning about God's teachings through his prophets from their spiritual guides. Jesus called them "blind guides" leading others into the same pit that they would fall into. (Matthew 15:12-14)
I am also an escapee from that system.
True Christians are still in the world, but like Jesus' illustration of the "wheat and the weeds", the "field" is overgrown with "weeds"...imitation Christians who are such in name only. Only a relative "few" would be found on the road to life. (Matthew 7:13-14)
There is a certain criteria by which the real Christians could be identified....I can provide it if you like....straight from the Bible....?