Islam considers the Qur'an to be authoritative only in its original language. Many teachings even claim it is a sin to read in any language but it's original, and while not all adhere to this belief, learning Arabic specifically to read or recite the Qur'an is common even in countries where it is of no other use.

On the other hand Christians openly encourage translations into other languages.

What does Christianity believe about the Bible that makes this possible? Are translations generally considered authoritative in their target languages in the same way that the original text was?