Ye Shall Testify
As Joseph was translating the Book of Ether in the Book of Mormon, he learned that three special witnesses would be able to see the plates. Section 17 is a revelation to Oliver Cowdery, David Whitmer, and Martin Harris, who would be the three special witnesses. Through their faith, they were able to see the gold plates, the sword of Laban, the Urim and Thummim, and the Liahona. They were commanded to testify of the things they had seen.
We too can be witnesses of Jesus Christ and the Book of Mormon. As we gain and strengthen our own testimonies, we can testify of the things we believe and know to be true.