I believe the voices come from afar, to guide or torment me, by way of good and evil spirits.
Jung made a differentiation between mind and psyche, and he called the psyche the mind taken together with all the influences on the mind.
Looked at in this way, the psyche can be considered to include both angels and demons, that regularly influence our thought.
Saint Ignatius of Loyola gave an important means of discerning the spirits. He said that we must examine the thought carefully, in its beginning, all through its middle, and in its end. He said that if the thought comes from a good spirit, it will be good in the beginning, all through the middle, and in the end. If not, then it did not come from a good spirit or from God.
I think we all experience angels’ and demons’ influence on a daily basis, but we are so used to it we don’t think of it as out of the ordinary. It is, in fact, the ordinary functioning of our psyches.
I see God’s influence as slightly different from the angels and demons, in that we have in us an aspiration to seek God, which comes from God, and that is part of the way God guides our thoughts. So that, there is the striving within my own spirit, to seek the truth, to seek love, and that is a big part of God’s influence on my actions, in addition to my thoughts.
Sometimes I experience myself asking myself something, and it seems to me I am asking my brain for the answer, the way we sort of (most of us) used to think about computers before we became more familiar with them — more like HAL or the computer on the bridge of Star Trek. They would ask the computer a question and the computer would come back with the answer. I find my brain works very well in this way, I can ask it a question and listen for the immediate answer, and on further investigation it is more often than not right. I find it quite useful and amazing, actually. It is as if my brain already knows how to process the question, and if I get my ego out of the way, my brain does its thing very quickly without me having to help it. What is normally called discursive thought is cumbersome in comparison.