* Different grammatical structures: Greek and English (or any other modern language) have vastly different grammatical structures. A direct, word-for-word translation would often result in grammatically incorrect and nonsensical English.
* Nuance and meaning: Words in Greek often carry multiple layers of meaning depending on context. A single Greek word might require several English words to convey its full nuance. A literal translation would lose this richness.
* Idioms and figures of speech: The Bible uses many idioms and figures of speech that don't translate directly. A literal translation would miss the intended meaning.
* Evolution of language: The Greek of the New Testament is different from modern Greek. A truly "exact" translation would require explaining obsolete vocabulary and grammatical forms, which would be inaccessible to most readers.
While some translations aim for a more literal rendering (like the KJV in some respects, or the NASB to a greater extent), they all inevitably make interpretive choices in order to be understandable and convey the meaning accurately. The goal of a good translation is not to be a word-for-word replica but to accurately convey the *meaning* and *intent* of the original text in a way that is clear and accessible to the target audience. Even the most literal translations involve choices about how to render specific words and phrases.