Within a paradigm where there is a deity who is capable of answering your prayers but does not always choose to do so, the very notion of praying doesn't make sense.
A deity, being omniscient, would already know what you want, and how badly you want it, and the arguments for giving it to you, regardless of whether you go through the motions of praying. The only scenario in which praying would make a difference is if the deity is not just, and is so insecure in its own divinity that it wants its ego stroked by people getting down on their knees and begging. But shouldn't any remotely competent deity be above that sort of thing?
As I was writing this, I found myself wondering if there's some correlation between capacity for religion and capacity for emotional labour. Religion (or, at least, the subset of religion to which I have been exposed) requires not just having certain feelings, but performing those feelings, often publicly. (Or, if not truly publicly, then at least so it can be seen by your family or your religious community or your religious leadership.) I wonder if being able to and willing to do that that might correlate with being able to and willing to perform emotional labour?
I don't think it would be outright cause and effect (in my case, I have far more desire to perform emotional labour than to perform religion, but far less ability), but nevertheless I do wonder if it correlates.