Even not being a Baha`i my self i can say that i agree to what is written in this quote you added
No matter if it was Buddha, Jesus, Baha`u`llah they become a part of God (or as you say the representation of) when they reached enlightenment, They then saw and understood the wisdom of truth. God in my understanding is Truth, But if we look at each representation of Truth that has been a spiritual teacher on earth, they all have their own wisdom, their own teaching, but they are all speaking the truth.
So for us who not yet have realized a form of enlightenment will be able to do so by following one of the spiritual teachers, and doing our own cultivation until we realize the truth too