It helps those who are grieving to see their loved ones. It is comforting to know that we are not alone in our grief. This comfort can help them survive as they come to terms with their loss.
A visitation may also be a way to help heal the soul of the loved one themselves. Especially if they have unfinished business. In this case the soul may be unable to rest until they have made their message known. The message may be something simple such as an apology that needed to be said to something as intricately delivered as the specifics surrounding the circumstances of their death.
The messages from these dream visitors can also give us information about moving from one stage of life to another. This can be signs of future reincarnation or other transitional news.
Sometimes when we dream of a lost loved one, it is actually a way for us to relive the best of our lives with our friend or family member. These dreams come from our subconscious and not from the spiritual realm.
When we are truly visited by a lost loved one, it gives us hope that we are never truly alone and that we should have faith in God and in an Afterlife.