Pre-existence

Discourses of Brigham Young, pg. 58; “We had an existence before we came into the world. Our spirits came here pure to take these tabernacles; they came to occupy them as habitations, with the understanding that all that had passed previously to our coming here should be taken away from us, that we should not know anything about it. 3:367.”

John 3:13; “And no man hath ascended up to heaven, but he that came down from heaven, even the Son of man which is in heaven.”

You’ll notice the phrase “…but he that came down from heaven…” is used in the singular sense.  It doesn’t say “those that came down” or us or we or they or them, but “he”.  No one but “He has come down from heaven”, making it impossible for anyone to live in a pre-existent state.

 Also take note of 1 Cor. 15:47 which says “The first man is of the earth, earthy; the second man is the Lord from heaven”.

That first man referred to here is Adam.  Adam is from the earth.  In fact, his name in the Hebrew is àdàm meaning ruddy, red, or from the earth.