The creation of the world is spoken of as if the world were a building and the foundation was the first part to be constructed. AT: "since God began to create the world" (See: [[rc://en/ta/man/translate/figs-metonymy]])
This speaks about sin as if it were an object that a person could put away. Putting sin away represents forgiving it. AT: "to cause God to forgive sins by sacrificing himself" or "to sacrifice himself so that sin can be forgiven" (See: [[rc://en/ta/man/translate/figs-metaphor]])