Often dream of deceased people due to the stress, resulting from the loss of someone close to them. Going to bed, you scroll in memory all of the day's impressions and experiences, which are then transformed into dreams. In the end, the person sees what he thought and what he has been through lately.
Impressionable people the dead man can dream after watching the movie or any of the series. This is because some points are deposited in the consciousness and comes to mind only in the night.
Sometimes a dead man can dream as a sign or warning. Such dreams are considered to be message. It is in these dreams through a deceased person can enter any important information. For example, sleep may be lost a relative and tell you about any impending misfortune. Sometimes the dead can point to someone's death may soon take the next one. Very often the relatives can just remind yourself that you don't forget and for a while came to him to the grave and brought flowers.
From a Church point of view, to believe the dreams that are dead, absolutely not worth it. This is due to the fact that dreams are sent from God himself to be extremely rare and must be authenticated by a cross and prayer. And the other dreams with dead people is leprosy of the devil and demons who are trying to incite you to commit a particular action.
To give a definite answer to this question is simply not possible, as everyone has their point of view, is unique and follows his views and beliefs. Someone do the dead dream as a warning, others due to stress, grief or experiences, others just do not have enough close friends, and they always think about the deceased. Whatever the reason for such dreams should not worry and take this very seriously, it is best to go to Church to pray and light a candle for the repose of the deceased person.