From these scriptures we learn that there were about three hundred souls who saw and heard much; the Holy Spirit of God did enter into their hearts; they were filled as if with fire; they could speak forth marvelous words; a pleasant voice whispered, saying: Peace, peace be unto you; angels came down out of heaven and ministered unto them.
My question is: “How could three hundred souls be baptized with fire and with the Holy Ghost and know it not? How do people know when they've been baptized by fire?”
“And it came to pass that when they cast their eyes about, and saw that the cloud of darkness was dispersed from overshadowing them, behold, they saw that they were encircled about, yea every soul, by a pillar of fire.
And Nephi and Lehi were in the midst of them; yea, they were encircled about; yea, they were as if in the midst of a flaming fire, yet it did harm them not, neither did it take hold upon the walls of the prison; and they were filled with that joy which is unspeakable and full of glory.
And behold, the Holy Spirit of God did come down from heaven, and did enter into their hearts, and they were filled as if with fire, and they could speak forth marvelous words.
And it came to pass that there came a voice unto them, yea, a pleasant voice, as if it were a whisper, saying:
Peace, peace be unto you, because of your faith in my Well Beloved, who was from the foundation of the world.
And now, when they heard this they cast up their eyes as if to behold from whence the voice came; and behold, they saw the heavens open; and angels came down out of heaven and ministered unto them.
And there were about three hundred souls who saw and heard these things; and they were bidden to go forth and marvel not, neither should they doubt” Helaman 5:43-49.
“Behold, it was the faith of Nephi and Lehi that wrought the change upon the Lamanites, that they were baptized with fire and with the Holy Ghost” Ether 12:14.
“And ye shall offer for a sacrifice unto me a broken heart and a contrite spirit. And whoso cometh unto me with a broken heart and a contrite spirit, him will I baptize with fire and with the Holy Ghost, even as the Lamanites, because of their faith in me at the time of their conversion, were baptized with fire and with the Holy Ghost, and they knew it not” 3 Nephi 9:20.