Jacob’s people, who lived the law of Moses (Jacob 4:5), believed in the atoning sacrifice of the scapegoat on the Day of Atonement. So why not talk about the Atonement of Christ? It is just as logical. In fact, the symbolism of the scapegoat and many other aspects of the Law of Moses were indeed meant to point people to Christ.
The Hebrew word for atonement did not have the same meaning of at-one-ment that we see in its English form. Rather, the Hebrew has more the concept of "covering" sins so they cannot be seen. Only then can one appear before the Lord.