"Some teachers teach to separate life further so you create a witness or observer consciousness, I have questioned this myself for some time and my conclusions are that some of them don't know what they are really doing and the others create the observer as a tool in order for you to create some distance from your conditioning and personality structures in order that you can gain some freedom from them and see that the don't define you. But at some point that witness or observer has to be let go of too in order for you to see reality directly."
"To say that teachers teach to separate life further so you create a witness"
The witness is an important step in our evolution and it is absolutely real, it is the individualization of Consciousness within every human being, it is not present from the beginning as some say it is a function of our evolution towards wholeness.
As Nisargadatta said " The witness is the touch of the real within the unreal".
It is not created as a tool, it is 100% real, it is a shift in identity, it enables you to go beyond the mind, the no-mind, but includes the mind and the ego. Abiding as a witness you actually become the witness from what i experience the witness or observer is actually the wrong word as it implies that this witness witnesses something, but in truth the witness just is, it can obviously choose to use the faculty of observing when need arise but it itself does not observe anything, it is perfectly self contained identity, which is you.
As the witness becomes fully who you are it surrenders into Consciousness which is the background of all the manifested creation. It merges with consciousness but still retain its individuality. Consciousness needs the witness ( you ) to be "born" so to speak. Most teachers do say that the witness has to be let go of at some stage, but again i disagree, you are the witness, which means you are the individualization of Consciousness , so yes at a certain stage you let go into consciousness and then into what some call the Absolute/Emptiness which is the container of Consciousness and of manifestation, but you remain, otherwise who realizes the Absolute, who says "there is only Emptiness" or " " There is only Consciousness" ( which by the way is not true) there must logically be someone there in the Absolute/Emptiness to say this, and it cannot be the Absolute as the Absolute just is, it is not cognizant of itself or of anything.
I would like to point out that these things i share with are just my own understanding that i have received through my teacher, i am still growing in experience and my intelligence too. I am only at the beginning.