One of the most common ways that spirits appear to the living is through dreams

But not, as many believe…..ordinary dreams. Instead, these dreams are often hyper lucid, incredibly real, and seem far more powerful and profound that even ordinary waking life or experience. There are lots of theories about WHY spirits tend to visit people in this state (often called “hypnagogic” experiences, as they take place in that weird space between wakefulness and sleep) but there are tens of thousands of these sorts of reports on record, and they are far more compelling than ordinary dream stories. (they are also typically far more important and life changing for the person who has one)

Here is an example of a very powerful, dream visitation experience. It’s from the great after death experience forum (nderf.org) – check the full story at the link following the short excerpt below.

The second experience was in 1990. My almost ninety-year-old grandmother had been in the hospital for a couple of weeks. Her body was shutting down and they didn’t expect her live much longer. Early one morning while I was still asleep I suddenly was engulfed in an incredibly bright light. Even though it was extremely bright, there was still a darkness around it. I knew this Light to be God, the Source, and the Creator of all. There was an even brighter core to the Light, which was off to my left. I either couldn’t turn to look at it or I just chose not to because right in front of me was my grandmother. She was staring directly at the center of the Light. I didn’t make out a body. All I could see was her face. I didn’t recognize her face because she looked to be about thirty years old. I just knew it was her. Her face was glowing and she was grinning from ear to ear. I don’t know if she knew I was there or not, because she was in such awe of what she was experiencing. I was in awe also. The light enveloped and permeated every ounce of my being. I felt the indescribable love, peace and security that no earthly terms can explain. It felt like I was swaddled in an eternal security blanket. I could not feel any fear or have any negative thought whatsoever. It just didn’t exist there. In fact-seeing my grandmother there- I knew she had passed on but it never occurred to me that she ‘died,’ because death would have had a negative connotation. I don’t recall how long this had lasted because time had no meaning there.

http://www.nderf.org/Experiences/1joseph_s_nde.html