If there is someone who is dead in real life that is alive in your dream, then you are realizing that your connection with him or her is still very much alive. See Awake.
If a person sees himself as alive in the grave he will either be imprisoned or he will find himself in some straitened circumstances.... alive in the grave dream meaning
To dream of being eaten alive, represents a part of you or your life that you wish would leave you alone and stop creating a nuisance. It may also mean that your actions are disconnected from your emotions.
If you were eaten by an animal in your dream, also look up that animal in this Dream Dictionary for further meaning.
If you were eaten by humans, look up “Cannibals”.... eaten / eaten alive dream meaning
You or someone else existing or being alive can represent: Perseverance.
Reliability.
A purpose or activity.
Recognizing the life-force, spirit, or soul within that person.
The person being on your mind right now for some reason.
Dreaming that a deceased loved one is alive can mean they’re on your mind, perhaps because you miss them or feel that you have unfinished business with them.
See also: Life; Light (Spiritual); Moving Around; Life Force; Alert; Surviving... alive or exists dream meaning