And there cometh a resurrection, even a ; yea, even a resurrection of those that have been, and who are, and who shall be, even until the resurrection of Christ—for so shall he be called.
At this point, Abinadi reveals the name of Christ to king Noah and his priests as if they don't know. Really? The Book of Mormon has mentioned Jesus Christ numerous times before this point. But what we need to keep in mind (and what makes the Book of Mormon so complex) is that it was put together long after these events from different sources, some of them being abbreviated. There are several subtle details that are easily missed, but demonstrate another case of both complexity and internal consistency of the Book of Mormon.
Abinadi's use of the name, Christ
Abinadi enters the scene in Mosiah 11 and in Mosiah 12 he starts his sermon. Not once is Christ mentioned by name until Mosiah 15:21. "Christ - for so shall he be called" signifies an introduction. After this, Abinadi mentions Christ by name 7 times in the remaining 25 verses of his sermon. We have seen some posts before demonstrating how many details Joseph Smith would need to keep in his mind and get straight, had he made this up. Making sure to mention Christ by name only after an introduction in the middle of the sermon (actually more towards the end), is another one of those. These details are sometimes so subtle that nobody even thinks about it. I didn't until very recently.
Zeniff's people's knowledge of Christ
Not only does Abinadi not mention Christ by name until Mosiah 15:21. He is not mentioned at all among the people of Zeniff. Abinadi started preaching during the reigh of King Noah, Zeniff's son. Unlike Noah, Zeniff seemed a righteous king. But even though Mormon quotes directly from Zeniff's writings in Mosiah 10 and 11, Christ is not mentioned at all. It is obvious that his name was not common knowledge among the people of Zeniff and Noah. How can that be? Surely, Christ is mentioned multiple times just a few chapters earlier in Mosiah. King Benjamin gave the people a new name. The name was Christ. They entered into a covenant and were born by Him becoming his sons and daughters.
But this is all just another demonstration of the complex, yet consistent narrative of the Book of Mormon, including subtle details. Zeniff and his group had already left Zarahemla when King Benjamin addressed the people. The reason is the Book of Mormon not always being chronological and Mosiah 9 starting with a flashback. In fact, Abinadi revealed the name of Christ to King Noah and his people in the land of Nephi a few decades before king Benjamin revealed the name of Christ to his people in Zarahemla. The reception could not have been more different. Here is the result from King Benjamin's speech
And now, because of the covenant which ye have made ye shall be called the of Christ, his sons, and his daughters; for behold, this day he hath spiritually begotten you; for ye say that your hearts are through faith on his name; therefore, ye are of him and have become his and his daughters. (Mosiah 5:7)
King Noah on the other hand, says
7 And he said unto him: Abinadi, we have found an accusation against thee, and thou art worthy of death.
8 For thou hast said that himself should come down among the children of men; and now, for this cause thou shalt be put to death (Mosiah 17)
The "new name" that King Benjamin would give his people indicates that the name of Christ was not common knowledge among the people of Zarahemla at the time. In that case, it is reasonable to conclude that it was not common knowledge decades earlier either, as Zeniff and his group went up to the Land of Nephi. That explains why Zeniff never mentioned Christ and Abinadi had to introduce him by name.
Access to the small plates of Nephi
Is it really reasonable to think that the people of Zarahemla, led by a righteous king, did not know Christ by name? Then why is "Christ" found multiple times in the Book of Mormon prior to these events in Mosiah? We need to keep in mind that everything prior to Mosiah in the Book of Mormon is taken from the small plates of Nephi. They were considered sacred and contained sacred knowledge revealed by angels. Nephi has this to say about them:
And an account of my these plates shall be given hereafter; and then, behold, I proceed according to that which I have spoken; and this I do that the more sacred things may be for the knowledge of my people. (1 Nephi 19:5)
Since Nephi has just mentioned the large plates, I assume "more sacred" is in comparison with them. Perhaps the small plates, for this reason, were not copied and distributed among the people and the name of Christ was not taught and generally known in Zarahemla until King Benjamin gave his speech. Similarly, the people of Zeniff and Noah had no access to the small plates of Nephi that were in King Benjamin's possession, and had to learn the name of Christ from Abinadi (who might have learned it from an angel?).
It all makes sense and remains consistent, but we need to study deep and pay attention to the details to realize it.
A reasonable question to ask about all this is what "Christ" is doing in the Book of Mormon at all, being a Greek translation of the Hebrew, "Messiah". Obviously, Christ is just the English translation (because that is considered his name in English) of an unknown word/name in the Nephite language. We don't know what that was. We only know that it was considered sacred, it was only revealed on certain occasions and it had special transforming power.