In a modern revelation the Lord repeated his prophecy made to his Apostles about the destruction of Jerusalem in A.D. 70. “And when that day shall come, shall a remnant [of Israel, the Jews] be scattered among all nations; but they shall be gathered again; but they shall remain [in their scattered condition] until the times of the Gentiles be fulfilled....
And when the times of the Gentiles is come in [that is, speaking in retrospect, when the restoration of the gospel takes place], a light shall break forth among them that sit in darkness, and it shall be the fulness of my gospel but they receive it not.” That is, there are many in the dispensation of the fulness of times who refuse the glories and wonders of the Lord’s new and everlasting covenant. “For they perceive not the light, and they turn their hearts from me because of the precepts of men. And in that generation shall the times of the Gentiles be fulfilled.” (D&C 45:24, 25, 28-30.)
In the ultimate sense, it appears that the fulness of the Gentiles-the time when the gospel goes on a preferential basis to Jews and Lamanites-is millennial. “When will the Lord take the gospel from the unbelieving Gentiles? It will be when the fulness of he Gentiles is come in when he remembers the covenant made with his own people, when the hour for millennial glory has arrived.’ (Bruce R. McConkie, Millennial Messiah, p. 241.)”