FIrst Nephi Chapter 5

In this chapter we see a family rejoicing at discovering one's familial connections through genealogy. A desire to belong, and to know where one belongs, seems to be an innate characteristic of the human condition: witness the longing of adoptive children to find their biological parents; the formation of gangs in fatherless inner city neighborhoods; the statistical probability of psychological well-being if raised by one's own two married parents.  This longing, I believe, is God-given, a call for us to become sealed to and linked to the great family of God, through temple covenants, which connect us and seal us to the family of Abraham, and the family of Noah, and the family of Adam, as God's children and sons and daughters.

Of all the hundreds of stories about their ancestors which the family of Lehi learns about as they study the brass plates, they seem to focus their attention and find it to be of particular importance to remember that their family was "led out of captivity" by God.  1 Nephi 5:15.

Remembering when one's ancestors were in captivity, and remembering that they were led out of captivity, seems to be a recurrent theme throughout the Book of Mormon. (See for example Alma 36:2, and Alma 36:29, in which the remembrance of captivity and of being led from captivity, is incorporated into the early and latter portions of the chiasmus of Alma the Elder's repentance-focused serrmon to his son.)

I believe the key and primary reason for this focus is because of its symbolic value in emphasizing and reemphasizing the central message of the Book of Mormon: that Christ has delivered us from the captivity of death and sin.  It is this message, and what we must do to benefit from that deliverance, which should be our focus when we read the scriptures, as it seemed to be for Lehi's family.