Beren and Luthien themselves - rescued the Silmaril from Morgoth's crown.
Yes, this was a valiant deed, but besides proving their undying love for
each other, I'm not sure what else it did.
Dior - killed some of Feanor's sons. Besides that, I don't think he did
anything spectacular.
Elwing - the wife of Earendil. Again, a character based around love and the
Silmaril
Elrond - hmm. fought in a few battles, gave some good advice.
Elros - I'd consider Elros to be one of the most important descendents of
Luthien, since without him, there would not have been Aragorn (who I would
think would have a great amount of responsibility for overthrowing Sauron).
Arwen, Elladan, Elrohir - Arwen's the wife/love of Aragorn. That's
basically her only role. The boys look like Noldor lords and are messengers
for dad. (excuse the chipiness here) Although, I suppose it could be said
that without Arwen, Aragorn wouldn't have had the incentive to do
everything he did.

and just for fun, let's look at Idril and Tuor
themselves - survived the fall of Gondolin, Tuor gets to be the first man
counted among the elves in Valinor.
Earendil - This I can understand. He played a major role in the Great War,
by killing Ancalagon and thereby destroying Thangorodrim. Plus, he's the
father of Elros.

oh yes, I almost forgot:
Eldarion - who, as far as we know, took the throne and admired the peace
that his father established.

So, there was Earendil and Aragorn (and possibly Arwen as a catalyst for
Aragorn). Were these two the greater purpose for the joining of elves and
men? Obviously for Earendil, Huor even knew that. Then is it safe to say
that the purpose of Beren and Luthien was to be foreparents of Aragorn and
Arwen?
This might be a pointless post here. If it is..please ignore.
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