When a priest is faced with the choice to either save his nieces life or uphold the laws of his religion the devil himself appears to tell him that everything he thought he knew about god and the devil was a lie to begin with.

I agree with most of dpg's unpacking of your story; except that, without knowing why the priest can't both save his niece and follow the rules of his religion (is there an inciting incident that would clarify that) or even what is the priest's religion, then how can we be sure that the devil here is truly the antagonist? Furthermore, you have the devil appearing after the priest finds himself in the dilemma of choosing his niece or his religion, so isn't the real struggle with the priest himself (perhaps with his faith or his own character). Finally, if the god and the devil you are writing about is actually God and Satan, then the devil wouldn't call himself a liar, but if he did, then the priest would not be confused by that statement, because he would already know and understand the character of the devil.

One thing that is not mentioned, and maybe it's just me, but for some reason the genre is unclear. The words "Evil" & "The Devil" make me think it is horror. But is listed as Drama/Mystery. I see the drama but not the mystery. Maybe the priest "Sets off to discover..." might help.

One thing that is not mentioned, and maybe it's just me, but for some reason the genre is unclear. The words "Evil" & "The Devil" make me think it is horror. But is listed as Drama/Mystery. I see the drama but not the mystery. Maybe the priest "Sets off to discover..." might help.

>>Pondering over the obvious paradox

Akin to the famous Cretan paradox of Epimenides. But a story has to build from the starting point of the audience's common perception or viewpoint. In this case, the conventional roles of God and Satan, good and evil in Catholic theology.

While we're wading into theology this logline reminds me of the story of Job where the devil gets personally involved in the life of Job. But he gets involved to win a wager over an important spiritual issue: that Job obeys God only because it's a good deal for him to do so-- he's richly blessed. Take away all the he has, Satan argues, and he will curse you. So God allows Satan to take all he has including his family.

What's your theme? What spiritual issue are you trying to explore in your story? What itch are you trying to scratch in pitting the devil against the priest like this?

The "why" is a very good point indeed. Unlike the reader, I know what the devil's motives are, but not why he would pick this specific man to satisfy his curiosity. It's something that needs a little tweaking.

The credibility is the catch. Of course you would think, the devil is just trying to manipulate you, but your only source of information on that is the devil's opponent, which in this case would be god. If the devil told you that he's a liar, would you believe him? If not, you would declare him honest and if yes, you would believe him and by that declare him honest as well. Pondering over the obvious paradoxon would make you end up listening to what he has to say and evaluate, whether you choose to believe him or not. It's a major sticking point of the whole story.

Let me see if I can unpack this.

There is a protagonist-- the priest.
There is a stake character -- his niece.
There is an antagonist -- the devil.
There seems to a genuine dilemma --the priest can either obey the teachings of the church or save his niece's life, but not both.

So far so good.

But... why of all the people, of all the priests in the world, is the devil taking time out of his busy schedule to jive-talk this priest? In other words, what's the causal connection? What is there about the priest's dilemma that triggers the devil to get involved? What's the point of his personal intervention?

And then there's the issue of credibility. Why would the priest believe anything the devil says when the Bible says the devil is the father of lies in John 8:44, a scripture the priest is likely to be quite aware of. So he would seem to be inoculated from believing anything the devil says.

Unless.. and I don't know what that 'unless' could be.

fwiw.