Personally I've never heard audible voices in my head. At the same time I have experienced a marked improvement in my mental health as I have replaced imposed religious thinking (my "cult self" or "cult identity") with organic spirituality which resonates with my "authentic self" or "authentic identity". I now identify as SBNR (Spiritual But Not Religious).
From experience I believe that God and his enemy both "speak" to all of us all the time.
Trauma it seems creates strongholds and channels for unhelpful thoughts to be introduced and acted upon.
Personally I would trust orthodox Psychiatrists only for a diagnosis of Schizophrenia. Their reductionist one-dimensional bio-medical models of health and illness leave many addicted, chemically doped, restrained, stagnant, and without hope.
Psychologists (talking medicine), and progressive Psychiatrists operate well outside the confines of the orthodox Psychiatric model. Names like Carl Jung, Stanislav Grof, George L Engel, Morgan Scott Peck, Peter Breggin, and Al Siebert come to mind.
For a hope filled article on Schizophrenia: Beautiful Minds Can Be Recovered (Source 1, Source 2 )
In relation to Abraham, religionists have deliberately hidden and obfuscated many dimensions of the Abrahamic Promise, which have great healing potential, for all that afflicts us humans. If so-called Christians, Jews and Muslims all saw, understood and embraced these dimensions the inane and hostile sectarian walls that that divide them would crumble. I speak from experience, and as one who identifies as a SBNR Christian, Jew and Muslim.