Adventist -> I'm not overly sure, but I think there are various strains of them and one at least that I know of, is a Michael/Jesus follower.
He would have to confirm it himself, as I can't speak for him, I was basing my thoughts on links he gave me, or links he placed on H/C, re the pre-existing Jesus and a literal pre-existing Son. Pre-existing son as in, not only becoming a Son at the birth from Mary, but before.
The line is, to send a Son, you needed to have one to send.
But the timeline of the Son and the actual sending, is clearly shown here -> Gal 4:4 - But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law,
John 17:18 - As thou hast sent me into the world, even so have I also sent them into the world. (Sent after his Baptism).
17:16 - They are not of the world, even as I am not of the world.
