Franklyn
I see this film to be a debate about religion, faith, fate, delusion, trauma and loss. Each of the three central characters have experienced some sort of trauma or loss in their past. Preest/David lost his younger sister as well as having experienced the trauma of war as a soldier; Milo had lost his father as a child and then, more recently, had his fiancee leave him very close to the day of their planned wedding. Amelia had probably, though it wasn't explicitly said, been abused by her father as a child and her and her mother had left him as a result.
David/Preest's father was a man of religion and had said that the death of his daughter - David/Preest's sister was the will of god. Preest was unable to accept this and he blamed his father for the death of his sister. This, along with the trauma of war, had triggered a psychotic episode in him. He wanted to avenge the death of his sister and because he saw the death of his sister as so unjust, he took issue with religion as a whole. The line in the film "if god is willing to stop bad things happening but unable, then he is not omnipotent, if he is able but unwilling then he is malevolent, if he is neither willing or able then he is not a god" explains Preest's inner torment perfectly.
Milo has recently been through a break-up just before he was due to get married. He then starts to see a childhood friend/love interest, Sally. She is not real. He first saw Sally just after his dad died - a very traumatic experience - and began to see her again after the break-up of his relationship with his fiancee - another traumatic experience. He tells his friend the story of the story-teller who's stories became reality. At the end of the film when he meets Amelia, who looks exactly like his imaginary friend, Sally, it begs questions of fate. It also means that the story-teller is in fact Milo - What he believed became reality.
Amelia is slightly less significant in the film but she needs to be there for Milo's story to make sense. She is also incredibly beautiful so I don't mind her being in the film!
The caretaker at the hospital chapel, however, I cannot figure out the significance of. Is he God? Is he just a guy? Why did he disappear in the last scene?
Generally, though, I think this film just asks a load of questions rather than attempts to answer any. I think this is pretty wise, as the subject matter is so far-reaching and deep. It doesn't do anything as silly as to say that God planned anything, It doesn't say that Milo meeting Amelia is anything other than coincidence. It doesn't say that Preest is wrong or right to question religion. It doesn't try to be too clever or too profound. It simply asks questions that we all ask as human beings.