2 Nephi 33:1

"And now I, Nephi, cannot write all the things which were taught among my people; neither am I mighty in writing, like unto speaking; for when a man speaketh by the power of the Holy Ghost the power of the Holy Ghost carrieth it unto the hearts of the children of men."

When Nephi spoke he spoke with the Holy Ghost, and that Spirit was felt by the hearts of the listeners. Although I was not there to hear him preach, I can read his prophesies. If I have the Holy Ghost with me as I read, these words will be carried unto my heart and I can feel the original strength of these words.