I’m sure I’ll get flamed for this, but it’s fine.
I see the emergence of Islam as a good thing for Europe and the world for the following reasons:
Islam has a strong tradition of tolerance and justice, which Christianity never had and never will have.
Islam has a strong tradition of intellectual inquiry, which led to many of the scientific advances we enjoy in the west today.
If it weren’t for Islamic competition, it’s fair to surmise that we’d all still be living in caves, eating our children, and dying from diseases caused because we were too dimwitted to wash our hands. That’s what the west devolved into almost immediately after Christ slew Rome, and it wasn’t until the Muslims (who had continued to advance) were poised to take over the show that we partially rejected Christianity and got a bit of enlightenment back.
If there has to be religion, then we have a choice. In 1000 years, Muslims will be piloting starships to the edge of the galaxy, and the lifespan for humans might be 300 years. On the other hand, Christians will be living in sewers, unable to feed themselves, seeing things like stem-cells and high velocity physics as tools of Satan. No hard feelings Christians, but I know which side I’m on.