2 Nephi 29:6–9

Many will reject the Book of Mormon, thinking the Bible is sufficient. The Bible and the Book of Mormon testify that Jesus is the Christ.

6 Thou fool, that shall say: A Bible, we have got a Bible, and we need no more Bible. Have ye obtained a Bible save it were by the Jews?
7 Know ye not that there are more nations than one? Know ye not that I, the Lord your God, have created all men, and that I remember those who are upon the isles of the sea; and that I rule in the heavens above and in the earth beneath; and I bring forth my word unto the children of men, yea, even upon all the nations of the earth?
8 Wherefore murmur ye, because that ye shall receive more of my word? Know ye not that the testimony of two nations is a witness unto you that I am God, that I remember one nation like unto another? Wherefore, I speak the same words unto one nation like unto another. And when the two nations shall run together the testimony of the two nations shall run together also.
9 And I do this that I may prove unto many that I am the same yesterday, today, and forever; and that I speak forth my words according to mine own pleasure. And because that I have spoken one word ye need not suppose that I cannot speak another; for my work is not yet finished; neither shall it be until the end of man, neither from that time henceforth and forever.

President Boyd K. Packer said:

“You should know . . . that by recent decision of the Brethren, the Book of Mormon will henceforth bear the title ‘The Book of Mormon,’ with the subtitle ‘Another Testament of Jesus Christ.'”

(“Scriptures,” Ensign, Nov. 1982, 53.)