2 Nephi 31:1-3

2 Nephi is an interesting book.  Unlike 1 Nephi, you get very little history.  It contains teachings and principles that Nephi(1) fells are important.  We get an account of Lehi's final teachings and blessings on his posterity. Chapter 5 is Nephi(1)'s record dealing with the splintering of Lehi's family.  The remainder of the record contains important gospel teachings Nephi(1) feels are important and that his posterity (as well as his future readers) to know and understand.  We have Jacob's sermons and teachings.  We have extensive writings of Isaiah.  The book ends with Nephi(1)'s observations and commentary one what he's recorded.

I would like to look at what Grant Hardy calls Nephi's Appendix - The Doctrine of Christ.  This composes chapters 31-33.  As we read and examine his writings, keep in mind were reading the words of "old" Nephi(1).  This part of the record was written over a 10 year period, beginning 30 years after they left Jerusalem.  We learn this from Nephi(1)'s words:

28  *And thirty years had passed away from the time we left Jerusalem.
29  And I, Nephi, had kept the records upon my plates, which I had made, of my people thus far.
30  And it came to pass that the Lord God said unto me: Make other plates; and thou shalt engraven many things upon them which are good in my sight, for the profit of thy people...
34  And it sufficeth me to say that *forty years had passed away....

2 Nephi 5:28-30, 34 (Emphasis mine)

So we see that the record we are reading was written over a ten year period.  If we assume Nephi(1) was in his late teens when they left Jerusalem, when he writes Chapter 5, he would range from his later 40's to his late 50's.  He's been through a lot.  He has become the patriarch of his people.  They look to him for guidance and the preaching of the word.  As he writes this, he's got a powerful perspective about the importance of the gospel and the commandments of the Lord.

Please keep this in mind as we look at Nephi(1)'s writings.

Nephi tells why Christ was baptized—Men must follow Christ, be baptized, receive the Holy Ghost, and endure to the end to be saved—Repentance and baptism are the gate to the strait and narrow path—Eternal life comes to those who keep the commandments after baptism.

2 Nephi 31 - Heading (Emphasis mine)

1  AND now I, Nephi, make an end of my prophesying unto you, my beloved brethren.  And I cannot write but a few things, which I know must surely come to pass; neither can I write but a few of the words of my brother Jacob.
2  Wherefore, the things which I have written sufficeth me, save it be a few words which I must speak concerning the doctrine of Christ; wherefore, I shall speak unto you plainly, according to the plainness of my prophesying.
3  For my soul delighteth in plainness; for after this manner doth the Lord God work among the children of men.  For the Lord God giveth light unto the understanding; for he speaketh unto men according to their language, unto their understanding.

2 Nephi 31:1-3 (Emphasis mine)

Nephi(1) tells us that he cannot tell all he knows will come to pass; but, he still needs to speak about the doctrine of Christ.  In doing so, he assures us he will speak plainly.  This way, we will better know and understand his teachings.  This is important because Nephi(1) is prefacing some very powerful and important teachings that will follow.

6  For the LORD giveth wisdom: out of his mouth cometh knowledge and understanding.

Proverbs 2:6

13  Happy is the man that findeth wisdom, and the man that getteth understanding.

Proverbs 3:13

9  For this cause we also, since the day we heard it, do not cease to pray for you, and to desire that ye might be filled with the knowledge of his will in all wisdom and spiritual understanding;

Colossians 1:9