I'm not familliar with the texts you quoted but from the actual quotes it would seem that it only definately refers to particular prophets, not all humanity.

A quick google turns up a late date of 1stAD for 2 Enoch, but a much earlier date for 1 Enoch, while 3 Enoch seems even later (Medieval even).

Wiki article on Smith Book of Abraham, is this what you were refering to?

http://en.wikipedia.org/wiki/Book_of_abraham