I am not sure why this is even debated. Knowing, with nicholas cage, is clearly about Scientology. I liked the movie a lot, and being about a religion is not necessarily bad. Ten Commandments was about a religion, Passion of the Christ was about a religion. Just because a movie is about a religion does not mean it is a terrible thing to enjoy and expand your mind with.

Here is proof that Knowing is about Scientology:

Knowing means Scientology
Lucinda is born in 1952, year of Scientology creation.
Nicholas Cage is a Scientologist.
Aliens bringing humans to start a new world is how humans got to earth (as Scientology believes).

Story closely resembles “Scientology, A History of Man” by L. Ron Hubbard.
No ad placement. No smoking. No one holding a coke. Nothing. No one would want their ad placement in a Scientology movie.
the symbol of Scientology as the space ships rose into the sky.

What else can you find which links the movie to Scientology?