Flick Check: X-Files: I Want to Believe: X-files, the TV show, generally succeeded when the Woo-Morgan team took control of the episodes. It achieved undying brilliance when Darin Morgan penned the script. But, it was a dreary mess anytime the series creator Chris Carter got all high-minded. X-files: I Want to Believe is a pure Chris Carter morality play, meaning it is the dreariest of messes. As a one hour TV show episode it would have been lame. As a feature film it's drudgery. It just leaves you asking innumerable questions that begin with "Whatever possessed them to..." until you just stop and write-off a couple of hours of your life rather than try to fathom the thinking behind it.
My suggestion is to turn the franchise over to Charlie Kaufman for the next film. Or just skip it altogether. Which is what you should so with this movie.