Precisely why it’s worth considering in the development phase, even if there is no direct reference to religion within the story.

Is a person motivated a promised reward in an afterlife? Is reincarnation a possibility? What is the purpose of life?

It influences the exclamations one might utter: “praise the lord”, “by the nines!”, “gracious spirits”, “may the wind guide you”, “devils take you”, “thank the goddess of the second moon”, “hell hath no fury like...”

Do people leave offerings? Do they pray? When they are in the depths of despair what are their thoughts? If one chooses to feed a beggar, why do they do it? Because a god or goddess dictates it is right or simply because they feel it is their responsibility to make the world better for the next generation or any other reason?