Grief is a Journey
Grieving is feeling a loss. It can indeed be physical death, but doesn't need to be. It can be any death, including a way of feeling, thinking, believing, or being ~ or the way we thought "life was supposed to go". For some, anything we were "attached to" physically, emotionally, mentally, or spiritually and in this case, a person might be going through a spiritual initiation called a "dark night", "rotting", "emptiness" or "crucifixion".
Grief can be brought about by the