In the year 1600 Giordano Bruno was burnt at the stake for having different beliefs than the Catholic Church. The Jesuits had a most elaborate form of torture techniques that would make waterboarding seem uninspired from a psychopath's point of view. That is the kind of thing that ISIS has been doing.
Now we have a liberal pope. So why exactly is it that Islam won't be able to change? Yes, a liberal Islam would contradict what their holy scriptures have to say but the same thing applies to Liberal Christians who'd rather ignore the Old Testament.