Whell in my personal luck at things I think that spirit is what lets the other elements form somthing, and that we are a bland of the 4 others and spirit is whats inside us, so we aren't spirit, but what makes us us is spirit, that spirit is aur true form which lives on forever, even if aur body does not, this is my perspactive on spirit
In the pentacle or pentagram the five points represent the 5 elements of nature. As being the Spirit it's placed on the top point of the pentacle or pentragram. The spirit is mostly concidered apart of the four elements.
So if I am right, yes spirit is apart of the elements.