The scarlet letter’s significance oscillates throughout the novel, betokening now sin, now mercy and virtue. In this, it acts as a microcosm of the whole text, in which moral sympathies are established and then inverted. Furthermore, it’s a direct contradiction to Puritan belief, which held all signs to be immutable. This found its apotheosis in the concept of predestination, according to which all events were determined a priori by God.
In this instance, the scarlet letter's transformation once more allies Hester with the Virgin Mary. According to medieval chroniclers, a miraculous statue of Mary with her son on her lap and a burning taper in her hand was found on the banks of the River Teifi. Several attempts were made to move it to the parish church but on each occasion it mysteriously returned to the spot at which it had been found. Nor would the candle be extinguished: it apparently burned continuously for a full nine years. This legend gave birth to a lasting association of tapers with Mary's role as the bringer of the light of Christ and embodied the undimming purity conferred by her virginity. Mary of the Taper was the divinity to whom Catholics prayed for protection and recovery from illness. Puritans, of course, viewed the cult of the Virgin Mary as abominable idolatry: Hawthorne is drawing a sly parallel between their rejection of the mother of Christ, supposed to have conceived in a state of grace, and that of Hester, the adulteress, and in doing so calls into question Puritan conceptions of sin and purity.