I found a very interesting equation in this chapter:

Lehi says (v14)	The Lord is merciful	those who come unto him	will not perish
Nephi says (v20)	The Lord is merciful	those whom he chooses because of their faith	will be delivered

They seem to be saying the same thing, so we can perform some algebraic manipulation, and see what happens.

"The Lord is merciful" is the same in both.

"will not perish" is the same as "will be delivered".

So therefore, "those who come unto him" is the same as "those whom he chooses because of their faith".

Therefore (new equation): Those who come unto him are chosen because of their faith.

Those who come unto him and have faith

will be chosen will be delivered will not perish