Does the Book of Mormon teach that Christ was born in Jerusalem?
I’m guessing your question originates with Alma 7:9-10 (emphasis mine).
9 But behold, the Spirit hath said this much unto me, saying: Cry unto this people, saying—Repent ye, and prepare the way of the Lord, and walk in his paths, which are straight; for behold, the kingdom of heaven is at hand, and the Son of God cometh upon the face of the earth.
10 And behold, he shall be born of Mary, at Jerusalem which is the land of our forefathers, she being a virgin, a precious and chosen vessel, who shall be overshadowed and conceive by the power of the Holy Ghost, and bring forth a son, yea, even the Son of God.
Two things are important to note in verse 10. First, Alma says “at” rather than “in” Jerusalem. Second, he describes “at Jerusalem” as “the land of our forefathers”. To emphasize the significance of saying “at Jerusalem” rather than “in Jerusalem” (the phrase you used when asking your question), let’s look at something else Alma said two chapters later (emphasis mine).
Alma 9:1 And again, I, Alma, having been commanded of God that I should take Amulek and go forth and preach again unto this people, or the people who were in the city of Ammonihah, it came to pass as I began to preach unto them, they began to contend with me, saying:
From this verse, we clearly see that Alma’s language included the option of specifically referring to something as being in a city, yet he uses “at Jerusalem” in chapter 7. Let’s look at a something written by Nephi, which I suspect Alma had read, but regardless, the language, or phrasing, would be what was passed on from generation to generation (emphasis mine).
1 Nephi 1:4 For it came to pass in the commencement of the first year of the reign of Zedekiah, king of Judah, (my father, Lehi, having dwelt at Jerusalemin all his days); and in that same year there came many prophets, prophesying unto the people that they must repent, or the great city Jerusalem must be destroyed.
7 And it came to pass that he returned to his own house at Jerusalem; and he cast himself upon his bed, being overcome with the Spirit and the things which he had seen.
Here again we see use of the phrase “at Jerusalem” rather than “in Jerusalem”. In the first chapter his book Lehi in the Desert; The World of the Jaredites; There Were Jaredites, Hugh Nibley gives us an explanation of the significance and historicity of this phrase. (I’ve added links to the scriptures he referenced.)
When we speak of Jerusalem, it is important to notice Nephi’s preference for a non-Biblical expression, “the land of Jerusalem” (1 Nephi 3:10), in designating his homeland. While he and his brothers always regard “the land of Jerusalem” as their home, it is perfectly clear from a number of passages that “the land of our father’s inheritance” (1 Nephi 3:16) cannot possibly be within, or even very near, the city, even though Lehi had “dwelt at Jerusalem in all his days” (1 Nephi 1:4). The terms seem confused, but they correctly reflect actual conditions, for in the Amarna letters we read of “the land of Jerusalem” as an area larger than the city itself, and even learn in one instance that “a city of the land of Jerusalem, Bet-Ninib, has been captured.” It was the rule in Palestine and Syria, as the same letters show, for a large area around a city and all the inhabitants of that area to bear the name of the city. 9This was a holdover from the times when the city and the land were a single political unit, comprising a city-state; when this was absorbed into a larger empire, the original identity was preserved, though it had lost its original political significance.10 The same conservatism made it possible for Socrates to be an Athenian, and nothing else, even though he came from the village of Alopeke, at some distance from the city.11 This arrangement deserves mention because many have pointed to the statement of Alma 7:10 that the Savior would be born “at Jerusalem which is the land of our forefathers,” as sure proof of fraud. It is rather the opposite, faithfully preserving the ancient terminology to describe a system which has only been recently rediscovered.
Though he “dwelt at Jerusalem,” Lehi did not live in the city, for it was after they had failed to get the plates in Jerusalem that his sons decided to “go down to the land of our father’s inheritance” (1 Nephi 3:16), and there gather enough wealth to buy the plates from Laban. Loaded with the stuff, they “went up again unto the house of Laban” in Jerusalem (1 Nephi 3:23). The Book of Mormon employs the expressions “to go down” and “to go up” exactly as the Hebrews and Egyptians did with reference to the location of Jerusalem, and thus clearly establishes that Lehi’s property lay somewhere in the country and not within the walls of Jerusalem.12
This Bible map (from which I’ve extracted the relevant portions) shows just how close Bethlehem is to Jerusalem. In light of their proximity, and Nibley’s explanation of the way the ancients referred to regions, it’s entirely understandable for Alma to have said that Christ would be born at Jerusalem.
I hope that clarifies this verse for you. I highly recommend this Nibley book to all students of the Book of Mormon – it added to my interest as I read with increased understanding of the locations and culture of Lehi and his family (and the Jaredites).