Nephi here addresses a fourth category—those who will not accept the Messiah. Rather than edifying them, his words will condemn them. Although they disdain his testimony in life, after death it will condemn them at the last day.
Nephi’s “seal” is his formal closing testimony. Speaking as a prophet, he verifies its truthfulness, affirms its authority, and declares its eternal significance.
Text: This is the end of both this chapter and the book of 2 Nephi.