Why is Baha'u'llah's language archaic?

I have a friend who's Baha'i and I've noticed Baha'u'llah quotations are translated into an archaic form of English (ex. "Every age hath its own problem, and every soul its particular aspiration"), which died out well before he lived (19Th century).

Is this a reflection of the original language (meaning he deliberately spoke in an outdated fashion), or a choice made by translators? Either way, why?
@ Jimmy: Thanks for your response! I did consider this (I'm not too familiar with Spanish but I speak French, which has a similar T-V distinction; I assume that's what you're referring to?), but that doesn't account for usages like "the world needed" or syntactic choices like "abide not."

It sounds to me as if translations are trying to emulate King James Version-language, and I'm not sure why.

well if you translate Spanish to English the same exact things happen so no, it's not necessarily archaic.

Because English speakers have the absurd notion that is something sounds like the King James Version Bible, then that means its more sacred. What it really means is that your point isn't being made very clearly. Take a look at the Book of Mormon, Joseph Smith didn't even have half an idea about Jacobean grammar and it shows.

Now it might be the case that he did speak archaically for effect, in which case the translators might have wanted to get that feel across, but I bet it was to match the KJV.

Riaz Khadem, in his book "Shoghi Effendi in Oxford and Earlier" (George Ronald, 1999), notes that the Guardian discovered his appreciation for the English style of the "King James" translation of the scriptures through "The History of the Decline and Fall of the Roman Empire" by the historian Edward Gibbon:

"During his studies at Oxford Shoghi Effendi became familiar with a book of extreme importance, which captured his interest and left an enduring mark on the style of English that emerged in his later writings. He saw the similarity of the historical events described in the book with the decline of the social and political institutions of his time. Furthermore, he found in this book the germ of a style of English that could serve as the vehicle for the exposition of the spiritual and intellectual verities of the Faith of Baha'u'llah. This book, The Decline and Fall of the Roman Empire, Gibbon's famous work, was Shoghi Effendi's constant companion." (p. 128)

The language of Baha'i scriptures is formalized, a reverential style adopted by Shoghi Effendi owing as much to High Persian style as to the language of Gibbons and the KJV.