Matthew 22

Alma taught the people of Zarahemla -

"...there can no man be saved except his garments are washed white; yea, his garments must be purified until they are cleansed from all stain, through the blood of him of whom it has been spoken by our fathers, who should come to redeem his people from their sins." (Book of Mormon | Alma 5:21)

I believe our garments or our so called "robes of righteousness" takes place as we make and keep sacred covenants of baptism and in the temple. We sense this same teaching as the Savior gave the parable of the King's son saying -

"...when the king came in to see the guests, he saw there a man which had not on a wedding garment:
12 And he saith unto him, Friend, how camest thou in hither not having a wedding garment? And he was speechless." (New Testament | Matthew 22:11 - 12)

What do I believe the wedding garment to be in this parable? Nothing but robes of righteousness. This seems logical as -

"...said the king to the servants, Bind him hand and foot, and take him away, and cast him into outer darkness; there shall be weeping and gnashing of teeth." (New Testament | Matthew 22:13)

We are not only invited to the feast but are expected to come prepared dressed in the wedding garment or holiness.