I've read bits and pieces of both the Quran and Bible, but surely you cannot deny that quite a few things are rather open to interpretation? Which I'd say is the reason why, sadly, groups of people still kill or discriminate against each other over their interpretations, because they are as adamant as you are in the conviction they are correct.
It's a nice thing that you are so convicted of your faith and seem to know a lot about it, but I don't understand the insistence or conviction to state that everyone with a different opinion is simply wrong. Especially since other people who claim to be of the same faith say the exact same thing, but hold different convictions (I have a Muslim friend who uses your exact rethoric, albeit in a different language). It's the part of religion that's always irked me.
Re Monty Python, I think they were mocking the Bible, not mankind's ability to interpretate things