So just because the words haven’t been altered doesn’t mean you actually UNDERSTAND every word of the book. You haven’t made another version of Quran doesn’t mean you haven’t used your own translation to understand it. People go by million different translators in order to understand Quran. What remains the same is the message! If you believe that both books convey one message and both believe in one GOD and that’s the same GOD you believe in, then why can’t you swear on it?
This is exactly the kind of mentality that divides people.