Ecclesiastes 9:5

[Belacqua]

Do you agree with the motto of the New International Version that to modern readers the Bible appears like a cryptic reference book, but that it's not how it appeared to the original readers, and that, in ancient times, anybody who heard the God's word would also understand it?

I guess it depends on how far we go with "understand it." 

They'd probably understand the words. Hebrew or Greek speakers would follow what the sentences say, and then the Vulgate was probably quite readable for educated people. It's not intended to be tricky, like Finnegans Wake or something. 

As always we have to think of the Bible as a group of texts written by different people at different times for different purposes. Some will be straightforward narration, and other parts will intentionally be challenging. So for example I think the Book of Job's language will not be at all obscure, but its message might well be. I think it's wrong to read it like an Aesop's fable, where we can draw a clear moral at the end. It's more of a puzzle and a challenge -- a debate topic. 

Even if we assume it's the word of God, there are parables in the NT explaining why some people won't get it. The talk about how some seed falls on fertile ground and some on stony ground seems to indicate that people who hear the same words will accept them differently, so that some won't understand it deeply at all. “Let him who has ears hear" indicates to me that some won't get it. 

William Blake called the Bible "The Great Code of Art," for a couple of reasons. First, because it should be read as art and not as science, history, etc. Unlike those types of writing, it expresses its meanings through beauty, through suggestion, symbols, puzzlements. He also felt that because God's knowledge is infinitely beyond that of people, a Bible which was easily deciphered by people would be unholy. We work on it but, like God himself, it is infinitely beyond our capacity to understand.
 
So, no, I don't think the early readers grasped every word, or were meant to.

And I think that some verses in the Vulgate would confuse a native speaker of Latin. In Judith 8:34 in Vulgate, which is quite a literal translation of the Greek original, it says "Et revertentes abierunt.". Try to, without looking at modern translations, come up with a meaning which is both grammatically possible and logically possible. Can you? When I was reading the Bible in Latin, I was not able to. And, when I looked at modern translations, they seemed rather fanciful. I am no expert in Latin and Greek, but I think that passage would sound like an ungrammatical gibberish to native speakers of Latin and Greek.

I don't know Latin nearly well enough to judge whether "Et revertentes abierunt" sounds funny or not. The translators seem confident that it means something like "So they returned from the tent and went to their posts." Which I agree sounds a little rough, but the meaning is clear. In modern English maybe "So they left the tent and went..." would be more conversational. Each translation, though slightly different, seems to give it the same general meaning. It's true they seem to have added "tent" and "posts," probably to make it clearer in the translation. 

So it may be an idiosyncrasy of Latin grammar, or a textual degradation, or just sloppy writing in the original. I'm not educated enough to know. 

I do know that "come" and "go" sometimes work differently in other languages. For example in Japanese if you are making a quick trip to the store, you'll tell your wife "itte-kuru yo." Which literally means "go-come!" That's all: go-come! Which would be nonsense in a literal translation, but is completely natural in use.