How can we be sanctified and have our garments “washed white”? (Alma 13:10–11)
“As men exercise the priesthood, it has a purifying effect upon them. They become sanctified [holy] and the Atonement of Christ takes away their sins (v. 11). In addition to the priesthood, they are given the Holy Ghost, which is also a sanctifying gift if they receive it. Because of their pure and spotless [divine] nature, they cannot look upon sin without abhorring that sin (v. 12). Nonetheless, as the Prophet Joseph Smith said: ‘I love you all; but I hate some of your deeds’ (Teachings of the Prophet Joseph Smith, 361). Sanctification is not limited to a few, but to all who will magnify the priesthood and be guided by the Holy Ghost” (Nyman, Record of Alma, 176).
“Alma is obsessed with the image of the white garment: ‘There can no man be saved except his garments are washed white’ (Alma 5:21) [see Alma 13:11, 12; 7:25] . . . Such expressions forcibly call to mind the work of Professor [Erwin] Goodenough, in which he shows that the white garment had a special significance for the early Jews. God himself may be represented in the earliest Jewish art as one of three men clothed in white. . . . This image [from the Dura Europos synagogue] wasn’t even known to exist until 1958, but every time Goodenough goes back into the earliest Jewish pictorial representations he can find, there are the three men in white, or a single figure, the prophet, in white. The symbol of the chosen prophet, an emissary from God, is always the white robe, which is reserved for heavenly beings. Nephi says that the righteous shall be ‘clothed with purity, yea, even with the robe of righteousness’ (2 Nephi 9:14)” (“Echoes and Evidences from Hugh Nibley,” 485).