Question: If the thoughts, desires and feelings come from the soul and spirit, and the brain is just the mechanism to express and exercise those issues then what is the spiritual condition of a person that suffers from dementia? If his brain is not working right anymore what is going on with his spirit? My grandmother was a devoted fruitful Christian, and then at age 79 she developed some kind of brain deterioration that had the same as Alzheimer's symptoms.
Response: The brain is a physical organ of the body. Therefore, it is clear that any deterioration of that organ may severely restrict what the spirit is inputting. Sir John Eccles received his Nobel Prize for research on the brain. He describes the brain as: "A machine that a ghost can operate." To "operate" a "machine" clearly shows a distinction between the "brain" and the human soul and spirit (the mind), or what Eccles calls the "ghost." The mind of the individual operates the "machine" (the human brain), which subsequently causes the human body to function as needed (http://www.thebereancall.org/node/7230).
Thus, if there is a damaged "machine" (i.e., the brain), it is not the spiritual condition of an individual that is in question. The person inside can no longer "get out." A radio that has a damaged speaker or a short in the volume control can certainly not deliver a broadcast of the most carefully enunciated words. It is impaired. If Eccles's hypothesis is correct, a brain dysfunction would adversely affect a spirit's ability to effectively utilize the brain. That circumstance, however, cannot tell us anything about the condition of one's spirit.