In the previous scene of Williams's play, The Glass Menagerie, when Tom informs his mother that he has found a "gentleman caller," the stage directions read, "The annunciation is celebrated with music." With this direction the suggestion of Laura as the Virgin Mary is suggested since the Feast of the Annunciation is celebrated as the time that Mary was told by the Angel Gabriel that she would bear a child. 

1. In Scene 6, there are more religious words used in the stage directions.  For instance, as Laura stands in the middle of the parlor floor, her arms are lifted heavenward as her mother knees before her, adjusting the hem of a new dress, "devout and ritualistic."
2. As Laura and Jim sit on the sofa and converse, they reminisce about his role in The Pirates of Penzance, and Laura reveals to Jim that he attended the musical three times, the spiritual number of completion.  Further, as Laura relaxes with Jim, the stage directions again contain religious imagery:  "Jim ...smiles at Laura with a warmth and charm which lights her inwardly with altar candles."
3. Williams continues the images of altar and candles as Jim reveals that he has "strings on" him, he is engaged to a girl, like him, who is Irish Catholic.  As Laura struggles with the storm outside and within her, the stage directions this time read, "The holy candles in the altar of Laura's face have been snuffed out" as Laura's face has an air of "infinite desolation."  Then, symbolizes her further loss of Tom, Laura blows out the candles at the end of the play.  "She blows out the candles" just as the candles of the religious ceremony of the mass are extinguished when all is ended.