If you don't want some details about this film revealed, do not read further. First watch the film, then come back to find out why it's philosophically inane.
In the original short story, which is available online in the public domain, the story is essentially simple. God is adjusting the flow of cause and effect to achieve certain ends and some poor schmo discovers this. The book all but directly states that it is God.
The movie goes into much greater detail. It is God, the adjustment guys are angels, and they determine everything that takes place. In fact, the adjustment bureau is adjusting things all the time, we're simply not aware of it because anyone who would be aware of the changes has their mind adjusted as well.
They could have conceivably gone into Matrix-level questions of the nature of reality, only with regards to free will, but they don't. Lots of chases happen and no questions are asked aside from the usual, simpering, movie questions. And to really drive home how intellectually bankrupt the film is, it is the love of the two protagonists that achieves their deliverance.
Why God needs wacky gadgets is never explained. Why an omnipotent and omniscient God would need to adjust his plans is never answered. Why there is any difference between a God picking events to sway our destiny and random events doing the same thing is not addressed. That the brief mention of the "Dark Ages" indicates an all-knowing God that is woefully inept in world history isn't addressed. Why an all-powerful God needs agents to get this stuff done at all isn't addressed.
And, again, whenever the existence of God is known within a film, that results in a number of consequences. The fear of death is eliminated. As with The Lovely Bones, which Roger Ebert called deplorable, if we know that the afterlife is real, all of the drama associated with death is gone. Also, the simpering questions about whether the plan is always right or not is stupid. Of course the plan is always right! It was written by fucking God!
That's only a smattering of the questions that exist between the lines of this film. It could have asked them. It could have gone deep. It, importantly, could have ditched the religious aspect that makes no sense at all if you include the world outside of Europe and the US. But it didn't. And it's the worse for it.