Jehovah also provided the bible to help us grow spiritually, when we read, we get to know what God wants from us, we don't necessarily need a teacher to grow spiritually.
It's such an interesting read from you and I would also point out that even if we study the Bible, if we aren't able to understand, it might be difficult and the need for a spiritual teacher would be sought after who with his experience and knowledge would clarify things to us. It is now left to us to be willingly ready to learn too because no matter what they teach us, if we aren't ready, we can't understand.
Thank you for your thought
