This is a strange movie. I feel as though Knowing was entertaining, regardless of your like/dislike for Nicolas Cage. (I prefer him in The Rock, sidenote.)
It's got sci-fi, action, some Biblical references, and though disastrously dooming to the planet, quite entertaining and great special effects at the end.
Above all, it's terrifying in places. I did not think PG-13 was necessarily appropriate as a rating.
And last but not least, I'm just waiting for the fury this sets off about October 19th...
Questions: Is it angels or aliens? Literal or metaphorical?
Save $5. Rent it.