lordwea123 wrote:Beloved brothers! Perhaps our art is soon to mature,
For, since our times of youth, for long it has been brewed,
Soon to stand in calm beauty;
Be only pious, as the Greek were!
It depends on how close you want to stay to the German version. I've looked at two English versions of this poem and both stray pretty far from the original.
"Lieben Brüder!" is not a form of address. This usage is very unusual and one of the reasons I looked the poem up in the first place. I wanted to make sure that it's not a typo (it's not). If you wanted to say "Dear brothers!" (Liebe Brüder!) or "Beloved Brothers!" (Geliebte Brüder!) there would be no "n" at the end of the word. So to me this line sounds more like "To love, brothers!" however, the English versions of the poem take exactly the same approach as you did.
"Times of youth" is not literal either. In the German version Hoelderlin doesn't speak of a time period, he compares the art that matures to a young person.
I'd switch "be only pious" around to "only be pious" or "just be pious".
Disclaimer: I'm really not a expert on poetry in general or on Hoelderlin specifially. So please take everything I say with a grain of salt.