It seems to me that you don't understand what is to believe in something. Perhaps you buy into that false theory according to which Christianity is peaceful only because it was "reformed". This theory is compatible with moral and cultural relativism, which are today's social paradigms, but the problem is that it is completely and utterly false. Christianity has always contained the same sort of teachings and the Christian reformation was a return to these original teachings. Similarly, Islam has been reformed many times. The last big reformation movement is Wahhabism. As all reformation movements, it was a return to the original teachings of Muhammad, which are violent and will always be violent.
Within all religions there are different degrees of commitment among believers. Most Christians would not abandon everything to go and live among the poor like Mother Teresa did, but all Christians believe that helping the poor is the right thing to do. Islam teaches that Jihad against the unbelievers is the best of deeds. Not all Muslims are committed enough to die fighting, but the vast majority of them believes that Jihad against the infidel is essential to Islam. By the way, waging Jihad is not just killing people with a machine gun. Preaching Islam is also considered to be a form of Jihad. Giving money to organizations that promote Jihad against the unbelievers is also a form of Jihad.