The protagonist, Roselily, is getting married, and she seems to feel that she is leaving one kind of confinement or oppression only to enter another. The man whom she is marrying does not hold it against her, as her own Christian community does, that she has had several children with different men, all out of wedlock. This man is from Chicago, not from Mississippi, where the story takes place, where Roselily is from.
Their marriage ceremony is a Christian one, though the man Roselily marries is Muslim. During the ceremony, Roselily considers "ropes, chains, handcuffs, his religion," and thinks of how she "will be required to sit apart with covered head" in his house of worship. While Roselily considers her future with this man, she is aware of the way he judges her community, blames them, and so the phrase "teachings from the wrong God" helps to characterize him as someone who is not Christian and who worships a different god from the one this community does. Moreover, it characterizes him as someone who is strong and steadfast in his beliefs; he has clear ideas about what is right and what is "wrong," and he will, it seems, permit no compromise on this.
His religion is part of what worries Roselily about her future, the idea of being confined in new and different ways. She is eager to start over, to have "a chance to build" without being judged by others, "a chance to be on top." In the end, his hand "is like the clasp of an iron gate," unyielding and inflexible, just like Roselily imagines aspects of her future will be with this man.