Ironic that a film that centers around thematic issues of honesty would provide us with the most egregious example of false advertising in years. In case you don't know, The Invention of Lying is an anti-religious film, something we don't know going in and something we don't fully realize until halfway through the film when the Main Character tells his mom that yes, indeed, there is an afterlife. From here on out, Gervais is free to rant about religion and all the dishonesty that goes along with it. Instead of using this action as the Midpoint, it would have made more sense (and coincide better with the film's actual message) if it had been moved to the Act 1/Act 2 break. As it is now, it comes as a surprise and a bit of a disappointment.
But even more tragic is the absolute lack of any suspicion from the characters in the story. In a film dealing with thematic issues of honesty and lying, it only follows that there should be ample amounts of suspicion thrown in there as well. Leaving out this part of the argument creates a tremendous hole in the thematic exploration of the piece, something that didn't have to happen especially when you consider they already had a character ready made for it (Rob Lowe). Consequently we have a really hard time buying into the film's message and quickly dismiss it as soon as it is over (or in my case, even before it's finished).