Wheatley isn't really concerned with narrative poetry. Action isn't her thing; ideas are. She wants to praise things and talk about ideas, like Christianity, salvation, history. There's a little narrative in her poem though, when the speaker writes, "brought me from my pagan land." So, the speaker is a slave that was brought from Africa to America—by "mercy." And it's mercy that converts the speaker to Christianity, which she knew nothing about in Africa. Although people view her race negatively, the poem reflects her belief that anyone, even "Negroes," can be saved by joining Christianity. The end.