The Others (2001) accurately depicts the existence of alternate existences.

Rating: 9/10 (21 November 2001)

WARNING - POSSIBLE SPOILERS!
Not unlike the Sixth Sense starring Bruce Willis, this movie illustrates the existence of alternate existences or parallel universes/worlds/dimensions colliding and infringing upon each other.
Nicole Kidman's part is one in which she remained in denial of her own death (change in dimension), until proven otherwise by those in that dimension.
To fully understand the concepts illustrated therein, it is usually necessary to understand quantum physicists who believe in alternate realities/universes/worlds/dimensions, etc., or to have actually experienced same.
The movie is much appreciated for going out on a limb in that respect and is also considered "fiction with a purpose" since it teaches truths to those who are ready and/or willing to accept truths. Otherwise, it's just another scary movie containing a lot of darkness and fear.
Aside from quantum physicists' theories in re parallel universes, etc., there are some spiritual references to alternate realities, as well. One being from the teacher Jesus, his statement, "In my Father's house there are many mansions".