We discover the demon within ourselves through discernment, common sense and logic. If you are hearing voices, don't do what they tell you to do. Evil does exist and these people love to talk to, control and manipulate people on the earth. You can only imagine what kind of people out there who are so insecure that they would take advantage of our vulnerability here on the earth. Good exists as well and they like us to hear them too but they only want us to listen and learn. The good people out there will never tell us to do things. They are concerned only with inner transformative change.
All of us on the earth must, one day, follow this path. It is an initiation into our eternal lives. How we conduct ourselves, as we go through our own passion, determines where within this eternal society we belong. We must triumph over evil and in so doing overcome the challenges of life, of which there are many and find eternal community. This is why all of us are here on the earth, continue to live within the cycle of life and death; to gain the strength and wisdom to become and live with others who are divine.
If you have been diagnosed with paranoid schizophrenia, do what your psychiatrist tells you. I am not a doctor. I want you to find a way to feel well. In the whole scheme of things, just remember that God is with you in all of your challenges and wants you to understand that you are as beloved as anyone who exists. If you have any questions, please don't hesitate to ask.
Good luck and blessings in your journey-