Eternal life is the greatest of all the gifts of God. These verses give a simple formula for gaining eternal life. We must have faith (v. 14), repent, (v. 15), be baptized (v. 15) and then keep the commandments of God from thenceforth. If these four items are done, the word of the Lord is that he shall have eternal life. Does this seem too simple? Shouldn't there be other qualifications? Didn't Alma mean to include a few more requirements? Apparently not. The Lord has promised us eternal life if we do these four things.
The problem is that the fourth element requires a great deal of effort. It encompasses the concept of obedience to all of God's commandments and the concept of enduring to the end. It was this part of the formula which Nephi was speaking of when he said, ye must press forward with a steadfastness in Christ, having a perfect brightness of hope, and a love of God and of all men. Wherefore, if ye shall press forward, feasting upon the word of Christ, and endure to the end, behold, thus saith the Father: Ye shall have eternal life (2 Nephi 31:20).
Bruce R. McConkie
"Sometimes someone will say: 'Well, I have been baptized into the Church; I am a member of the Church; I am a member of the Church; I'll just go along and live an ordinary sort of life; I won't commit any great crimes; I'll live a reasonably good Christian life; and eventually I will gain the kingdom of God.'
"I don't understand it that way. I think that baptism is a gate. It is a gate which puts us on a path; and the name of the path is the straight and narrow path. The straight and narrow path leads upward from the gate of baptism to the celestial kingdom of heaven. After a person has entered the gate of baptism, he has to press forward with a steadfastness in Christ, as Nephi expresses it, having a perfect brightness of hope, and a love of God and of all men; and if he endures to the end, then he gains the promised reward." (Conference Report, Oct. 1950, p. 16 as taken from Latter-day Commentary on the Book of Mormon compiled by K. Douglas Bassett, p.34)