What are some voices that the Bible mentions? How come some of them mess with your head? Some tell you do things that you don't want to do and you know is wrong. Could you explain this and help me?
Our minds are amazingly complex. We are able to do many things at once and never give it a thought. I see things going on around me, while at the same time listen to a song or talk show on the radio, hold a conversation with my wife, drive the car with my hands and feet, and still have processing power left over to review what I need to do that evening. We can't even come close to being able to build a computer system as complex as the one with which we are born.
Unfortunately, some things can go wrong with the brain. Some come from genetic damage while others are chemically induced by drugs, still others are just temporary hiccups. While processing all the information that comes into it, the brain keeps track of the source. Almost every experiences a feeling of deja vu, a feeling that you have been some where before, though you know you haven't. Many scientist now believe that the the feeling is caused by a temporary confusion in the brain between long term and short term memory. The brain thinks for a moment that information currently being experienced is coming from its long term memory and thus you decide that you've been there before.
There are many other examples of this because your brain is divided into many specialized sections. There is an area that handles sounds and identifying the noise and interpreting some noise as words. Another section handles visual information and still another provides judgment. But what happens if there is a hiccup and concept being passed from one section to another is mislabeled and you believe that the concept had come from your ears instead of someplace else in the brain. The results would be very spooky because you would "know" that you heard something, but rest of your brain can't confirm it. For people who experience these hiccups, the "voice" is sensed as being more "real" than what is actually coming into their ears. When you begin to doubt reality, well, frightening is a mild way of putting the reaction.
For instance if you "overheard" (for lack of a better word) the part of your brain that makes critical judgment -- the part that tries to find the flaws in ideas or impulses, a critical part of you that keeps you from doing rash or foolish things -- if your brain accidentally labeled that process as an auditory input, you would think that someone was criticizing you, though no one appears to be there. If you overheard the part of the brain that was considering possibilities, you might think someone was asking you to do something that rationally (another part of your brain) you know would be crazy to do.
The heart is often used to describe thought because the emotional reaction to ideas is often felt strongly in the racing of the heart. As an example, in describing his silent prayer Abraham's servant said, "But before I had finished speaking in my heart, there was Rebekah, coming out with her pitcher on her shoulder; and she went down to the well and drew water" (Genesis 24:45). All people hear their thoughts as words, but when the source of those thoughts is mislabeled or we pick up concepts before they are fully filtered, it can cause deep confusion.
Psychiatrists try to help a person learn to recognize the difference between real input to the brain and apparent input. The person has to recognize reality and teach themselves that this is more important. The "voices" are just processing noise that might be useful, but more likely is better off ignored. There is a good personal account of this at http://www.geometricvisions.com/Madness/schizoaffective-disorder/voices.html If the cause is from taking a drug, then the person must stop taking it and hope that the damage can be repaired or at least dealt with.
The hearing of voices (auditory hallucination) and seeing things (visual hallucination) due to drugs and alcohol is mentioned in Proverbs 23:29-35. In particular the writer warns, "Your eyes will see strange things, and your heart will utter perverse things" (Proverbs 23:33). One of the great dangers of drugs and alcohol is that our perception of reality is distorted.