"Sins" represents the punishment for sin. AT: "to take the punishment we deserved because of our sins" (See: [[rc://en/ta/man/translate/figs-metonymy]])
Here "this ... age" represents the powers at work in the age. AT: "that he might set us free from the evil powers at work in the world today" (See: [[rc://en/ta/man/translate/figs-metonymy]])