Scriptural: Nephi provides the spiritual qualifications for the cleansing of baptism. We must follow the Son (meaning all of the commandments, just as the Son indicated his willingness to obey all commandments), have real intent, and repent of sin.
Nephi also adds that an important part of the preparation for the ritual is to “take upon you the name of Christ, by baptism.” This wording suggests that Nephi sees the ordinance of baptism as the symbolic event that effects this “taking of the name.” However, examination of the use of the phrase to “take the name of Christ” later in the Book of Mormon suggests that it is not inextricably tied to baptism. For instance, Moroni states:
Alma 46:18
18 And he said: Surely God shall not suffer that we, who are despised because we take upon us the name of Christ, shall be trodden down and destroyed, until we bring it upon us by our own transgressions.
Moroni is using the term as a group identifier, and indeed after the time of Alma and the formal establishment of churches, it becomes an identifier. However, Moroni uses the name as the identifier, not the fact of baptism. They would certainly have been baptized, but the taking of the name appears to have become a separate formality later in the Book of Mormon - a specific rite which could be enjoined upon the entire group listening to King Benjamin (Mosiah 5:8).
Part of the promise Nephi makes of the baptism is the receipt of the Holy Ghost. This is very clearly the meaning of the term “baptism of fire” as it is used in the Book of Mormon.
Translation: Joseph Smith understood the baptism of fire to be equivalent to the Gift of the Holy Ghost. That this is the understanding of this Book of Mormon passage is confirmed by the similar usage in the Doctrine and Covenants:
D&C 19:31
31 And of tenets thou shalt not talk, but thou shalt declare repentance and faith on the Savior, and remission of sins by baptism, and by fire, yea, even the Holy Ghost.
In spite of this correlation, the New Testament origins of the idea of a baptism of fire are interesting, and lead to a different interpretation of the meaning of the baptism of fire. This will suggest that the term “baptism of fire” in the Book of Mormon is due to Joseph’s borrowing of the phrase from the KJV New Testament, but applying it to a different conceptual designation.
The important New Testament texts are:
Mark 1:7-8
7 And preached, saying, There cometh one mightier than I after me, the latchet of whose shoes I am not worthy to stoop down and unloose.
8 I indeed have baptized you with water: but he shall baptize you with the Holy Ghost.
Luke 3:15-17
15 And as the people were in expectation, and all men mused in their hearts of John, whether he were the Christ, or not;
16 John answered, saying unto them all, I indeed baptize you with water; but one mightier than I cometh, the latchet of whose shoes I am not worthy to unloose: he shall baptize you with the Holy Ghost and with fire:
17 Whose fan is in his hand, and he will throughly purge his floor, and will gather the wheat into his garner; but the chaff he will burn with fire unquenchable.
Matt. 3:9-12
9 And think not to say within yourselves, We have Abraham to our father: for I say unto you, that God is able of these stones to raise up children unto Abraham.
10 And now also the axe is laid unto the root of the trees: therefore every tree which bringeth not forth good fruit is hewn down, and cast into the fire.
11 I indeed baptize you with water unto repentance: but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you with the Holy Ghost, and with fire:
12 Whose fan is in his hand, and he will throughly purge his floor, and gather his wheat into the garner; but he will burn up the chaff with unquenchable fire.
These are three recountings of the same incident. The language of both Luke and Matthew are dependent upon Mark 1:7-8, with the basic information from Mark being brought into a single verse for both Luke and Matthew (Luke 3:16, Matthew 3:11). What is interesting is not the correspondence, however, but the differences in both text and context.
The context in Mark is simply the person and mission of John the Baptist. The text before the cited verses simply introduce John. The following text begins the story of Jesus’ baptism. Note the changes in Luke:
Luke 3:15-17
15 And as the people were in expectation, and all men mused in their hearts of John, whether he were the Christ, or not;
16 John answered, saying unto them all, I indeed baptize you with water; but one mightier than I cometh, the latchet of whose shoes I am not worthy to unloose: he shall baptize you with the Holy Ghost and with fire:
17 Whose fan is in his hand, and he will throughly purge his floor, and will gather the wheat into his garner; but the chaff he will burn with fire unquenchable.
The first important change is context. Where Mark has the story appear in a simple discussion of John, Luke’s story occurs as an integral discussion about the Messiah. The common citation from Mark is the same citation about the relationship of John to Jesus, but in Mark it comes in response to a question that specifically examines Messianic possibilities. John defers a title of Messiah, but bestows it by implication on the “one mightier than I.”
The change in text is the ending verse. Verse 16 is not found in Mark, but appears in both Luke and Matthew’s versions. In the new context of Luke and Matthew, this added verse is important. Noting the added verse, however, may miss another very significant addition. In both Luke and Mark, John’s original statement that the “one mightier than I” would baptize with the Holy Ghost has added to it the additional “baptism” of fire.
Examine the same textual and contextual alterations in Matthew:
Matt. 3:9-12
9 And think not to say within yourselves, We have Abraham to our father: for I say unto you, that God is able of these stones to raise up children unto Abraham.
10 And now also the axe is laid unto the root of the trees: therefore every tree which bringeth not forth good fruit is hewn down, and cast into the fire.
11 I indeed baptize you with water unto repentance: but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you with the Holy Ghost, and with fire:
12 Whose fan is in his hand, and he will throughly purge his floor, and gather his wheat into the garner; but he will burn up the chaff with unquenchable fire.
Matthew’s text agrees with Luke, but the specific context does not. Rather than a discussion about the Messiahship of John, the context is one of the rightful children of Abraham, and in particular the righteous. In verse 10 Matthew places the statements of baptism in a context of a judgement, where the wicked are separated and burned.
It is this context of Matthew that is perhaps most instructive about the meaning both of the addition of the word “fire” in verse 11 and the addition of the entire verse 12. Verse 12 echoes the theme of verse 10. We have a purging of the wicked - a separation of the good from the evil. In both verses 10 and 12, the wicked are burned. This is a very common image in the Old Testament:
Ezek. 5:4
4 Then take of them again, and cast them into the midst of the fire, and burn them in the fire; for thereof shall a fire come forth into all the house of Israel.
Isa. 5:24
24 Therefore as the fire devoureth the stubble, and the flame consumeth the chaff, so their root shall be as rottenness, and their blossom shall go up as dust: because they have cast away the law of the LORD of hosts, and despised the word of the Holy One of Israel.
Perhaps the best reference for Matthew’s contextual examination of these passages comes from Isaiah:
Isa. 10:16-23
16 Therefore shall the Lord, the Lord of hosts, send among his fat ones leanness; and under his glory he shall kindle a burning like the burning of a fire.
17 And the light of Israel shall be for a fire, and his Holy One for a flame: and it shall burn and devour his thorns and his briers in one day;
18 And shall consume the glory of his forest, and of his fruitful field, both soul and body: and they shall be as when a standardbearer fainteth.
19 And the rest of the trees of his forest shall be few, that a child may write them.
20 ¶ And it shall come to pass in that day, that the remnant of Israel, and such as are escaped of the house of Jacob, shall no more again stay upon him that smote them; but shall stay upon the LORD, the Holy One of Israel, in truth.
21 The remnant shall return, even the remnant of Jacob, unto the mighty God.
22 For though thy people Israel be as the sand of the sea, yet a remnant of them shall return: the consumption decreed shall overflow with righteousness.
23 For the Lord GOD of hosts shall make a consumption, even determined, in the midst of all the land.
Isaiah presents two themes. The first is the burning destruction of the wicked (verses 16-19). This is followed by a redemptive section which exalts the righteous remnant in the midst of the destruction of the wicked who have not followed God’s ways (verses 20-22).
I suggest that is precisely this context in which Matthew, and to a less obvious degree Luke, ask us to see the comments of John the Baptist. In particular, what has begun as a discussion of the difference between the baptism of John and Jesus and become a theological statement of the Messianic mission of Jesus.
In Mark, the baptism of water is simply contrasted to the baptism by the Holy Ghost. This contrast between two baptisms is a very neat parallel to the contrast between the two performers of the baptisms. What changes in Luke and Matthew, however, is the addition of yet another aspect to Jesus’ “baptism.” Rather than only baptize with the Holy Ghost, Jesus will baptize with fire.
The context of the baptism by fire in both Luke and Matthew suggests that the baptism by fire refers to the apocalyptic cleansing at the time of the Messiah’s triumphal return. It is the burning of the wicked and simultaneous redemption of the righteous. It is Jesus in his Messianic role predicted by Isaiah and the other prophets.
In the context of the New Testament only, I suggest that the baptism of fire is distinct from the baptism of the Holy Ghost, and that it refers to the events of the end of the world when Christ will come in glory and his glory will “burn” the wicked.
This is most obviously not the context in which the term is used in the Book of Mormon. This should not be read as an “error,” but rather simply an appropriation of language. It is an artifact of the translation process, not of the theological meaning of the text.