How might this narrative be considered an allegory?

The Fall of Man and Loss of Innocence

Biblical parallels can be found in the appearance of Bertilak's castle (Paradise) and the role of his wife as temptress (Eve). Accordingly, Gawain loses his moral innocence when his value system is shattered by the end of the poem. Such an allegory emphasizes once more the poet's Christian message, and the relationship between mankind and the divine.