“My holiness is my salvation”
Let’s look at the words holiness and salvation.
Holiness indicates Purity, Wholeness, Innocence – all core qualities of Creation. Since you are a part of Creation—you did not create yourself after all—Purity, Wholeness and Innocence are your core qualities as well.
Salvation means release. Release from what? Release from identification with appearances. The Course sees the world as an effect. Salvation means release from identification with an effect and restoration to creative principle.
The statement “My holiness is my salvation” is about understanding and experiencing that your innate, unalienable Purity, Wholeness and Innocence release you from your identification with the world on the level of appearance and restore to you your awareness of your true identity. And with that release and restoration the world is released and restored as well.