TCM has an overview.
Wild Realm Reviews has a fairly detailed description of the characters and plots and says,
A minor classic, it's relatively unknown compared to such Christmas fantasies as Miracle on 34th Street (1947), It's a Wonderful Life (1946), A Christmas Carol (1938), but sometimes it's really pleasant to watch something a little less familiar in a similarly vintage vein.
The New York Times doesn't like it, ending its review with this:
All of it has been affectionately produced, handsomely photographed and sincerely performed.... It was in the story department that the ghosts played havoc with the script. "Beyond Tomorrow" should have gone no further than Christmas Eve. Even a hot toddy wears off when one travels into the chilly interstellar spaces.
I like it fine, as it makes a good alternative to those movies we watch every year. I do get a bit tired of the limited choices.... And this has an interesting view of the afterlife. And it has Maria Ouspenskaya.