While much of the verse is devoted to a description of the devil, or Satan, its purpose is to explain our fate were there no resurrection. We would become “devils.” If Jacob were speaking of the atonement, his meaning would be obvious. Certainly if we were unable to repent, our sins would eventually bring us the Satan’s level. However, Jacob does not discuss the atonement until the next few verses. Instead, he is speaking here of physical death—or the separation of the body and the spirit. Why would this condition alone ensure that we become devils?
Jacob is drawing on the theme of Satan as Yahweh’s accuser/opposite. Each is the conceptual opposite of the other. This theme was quite strong in the Ugaritic mythology that paralleled Israelite theology from at least 1350 B.C. to 1100 B.C. (See1 Nephi, Part 1: Context, Chapter 1, “The Historical Setting of 1 Nephi.”) Another opposed pairing is body and unembodied spirit. If the embodied spirit belongs to Yahweh, the unembodied spirit belongs to Satan through the extension of the conceptual opposition of the two.