The Hebrew language is the only language that I am aware of which was ever dead, and then "raised" again. ;) It was made the official language of Israel in 1948, after having been "dead" for 2000 years.
The language was never completely dead however. It was the language used for prayers by the Jews (and still is), and most Rabbis over the years would have known Hebrew. Jesus probably knew Hebrew, even if his everyday language was Aramaic.
What is fascinating about the fact that Hebrew has been dead for all those years is that the Hebrew language has not undergone the same amount of changes in these years as all the other languages. It was "frozen in time" so to speak. Modern Hebrew is surprisingly similar to Biblical Hebrew. The two are closer than modern English is to Old English.
Nevertheless there are differences of course. But I have found that Orthodox Jews tend to be able to understand the Bible in Hebrew at least somewhat. Some know it completely.
I only know a little Hebrew. So when I read the Bible, I mostly rely on the translation, but I always read a Bible that has the Hebrew right there so I can check it.
When it comes to the New Testament, I know NO Greek, but I use an interlinear translation, which tells you word-by-word what the Greek says.
So, to me, the translation is very important because scholars know Hebrew and certainly Greek FAR better than me. So I am relying on better scholarship than I would have to if I did not use a translation. However, I know enough to know not to trust the translation blindly.
I am a convert to Hinduism, and it does bother me somewhat that I must rely on translations of the Scriptures. I want to learn Sanskrit so that I won't have this problem. But it doesn't bother me in a spiritual way, just in a "scholarly" way. That is, as a religious studies scholar-to-be I feel the need to learn the original languages of the texts. But as for my spiritual life, I just rely on comparing translations, and I also have access to "interlinear" versions of some of the Hindu scriptures. (where they define each Sanskrit word one-by-one as they occur).
I believe it is important for believers in a Scripture to understand the original text. If they can not learn the language, then they really ought to make use of interlinear versions and the like, or at least compare different translations.