I first read this poem in Best Loved Poems of the American People. I'm pretty sure it was in the Humor section. My mother had pointed it out, because she had remembered it. When I was married, I met my ex-husband's Aunt Donna at some sporting event. The first words out of her mouth to me were "Are you saved?"
I thought "Seriously? This is how you greet a stranger, a new family member?" She didn't seem to be asking as if she wanted me to enjoy some great benefit she had, and was willing to step in if I didn't know the joys she knew. It was more along the lines of "Do you belong to my exclusive club and are you worthy of my presence, or are you one of them?"
I could totally see Aunt Donna narrating this poem. The woman in the poem is so sure of herself and her eternal place.
I've known many nuns who were taught that their mere status of being a nun earned them a ticket to heaven, no matter how they behaved. One reminded me of the narrator in a sad way -- her family of origin was really messed up, and she thought that if she became a nun, God would forgive them and they could get into heaven.
My own beliefs have varied over time, but I've held pretty steady to the notion that badgering people isn't going to get you into any sort of pleasant afterlife.