The author speaks of the world as if it were a building set on a foundation. Alternate translation: "since the creation of the world" or "since God created the world" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Doing away with sin represents having God forgive it. Alternate translation: "to cause God to forgive sins by sacrificing himself" or "to sacrifice himself so that God can forgive sin" (See: [[rc://en/ta/man/translate/figs-metaphor]])