A religion is not an abstract concept. It is a living, changing and evolving concept because at any given time it is a community of believers. Christianity in the Middle Ages was a far less tolerant community than it is today. The reason it is now more tolerant is largely because the experience of the Wars of Religion, the Enlightenment and the Post-Modern experience have radically changed the views of the people who profess it.

Islam today is going through violent and disruptive change. There are people preaching violence, and there are a lot of them. It is possible to read the Qur'an and justify this violence in it - the Salafists say that the Medinan surahs should take precedence over the Meccan surahs because they were written later, and the Medinan surahs have the problematic language that justifies killing non-believers.

While other religions can be interpreted to support violence, at the present it is Islam that IS being interpreted this way, and by a significant number of adherents. To attempt to equate religions is to wilfully ignore the reality in which we live.