Sadly being a peaceful Muslim who denounces these type of attacks does nothing to prevent them, it only gives credibility to the ideology that breeds the terrorists and fanatics. I would not partake in a religion that produces this type of atrocities unless I was forced to, which most Muslims are due to fear of apostasy.
Even if the religion in no way condoned these kinds of acts in it's writings?
The deeper problem with the types of people who become involved in planning and committing these acts are that they are typically targeted and encouraged to do this by others who use religion as a political tool and use their own reasoning, presented as religious truth, to justify them and encourage them. Even if they have no real basis in that religion. The problem is those who get deeply involved enough aren't likely to question what they are being told.
It's no different if you born here you would probably be a Catholic or a Protestant. Most people don't heavily identify with their religion because they have a choice not to. The difference is neither of those religions support atrocities and can be held accountable for their actions. Islam is backwards as it is organized like a cult and has no central figurehead or authority, and should be treated like one.
Cult: 1. A system of religious veneration and devotion directed towards a particular figure or object:
the cult of St Olaf
2. A relatively small group of people having religious beliefs or practices regarded by others as strange or as imposing excessive control over members:
a network of Satan-worshipping cults
Nothing like a cult so not sure why you insist on using that word. A religion doesn't need to have a central figurehead or authority. Most world religions don't to the extent you seem to be suggesting. Catholicism is one of the few examples.