Adding to Tom's information regarding change (or lack thereof) within the mooslum ideology...
All Christian faiths have evolved, not just the Roman Catholics.
One of the greatest historical and doctrinal changes was actually termed "The Reformation," and was initiated by Martin Luther in 1517. This gave birth to the Lutheran denomination, and shortly thereafter to the various Calvinist denominations--specifically the Baptists. This was followed by numerous additional mini-reformations led by folks like John Knox (Presbyterians), John Wesley (Methodists), Menno Simons (Mennonites), and countless others. The Mennonites themselves were an outgrowth of the Peaceful Anabaptist denomination which grew out of the John Calvin tradition.
Even in our recent history, several denominations have emerged, each with a desire to be more faithful to their interpretation of the Scripture, or to grant themselves some leniency for a particular ideology. Mary Baker Patterson Glover Eddie gave us Christian Science. Joseph Smith founded the Mormons. Numerous "second blessing" or pentecostal churches have emerged over the years.
And, though many of these denominations demand a strict adherence to their specific rules, and though many of these denominations require witnessing to the unsaved, none of the groups commonly accepted as Christian allow or encourage beheading those who do not agree with them.
Not since the Inquisition have we seen Christian denominations make war against non-believers. And never throughout Christendom have we seen the acceptance of rape and slavery as a scripturally sanctioned behavior over a conquered people. I know, we fought a war over the slavery question, and some sought to justify slavery by using scripture, but that was a relatively short period of time, and we "reformed" our way out of that quagmire.
As Tom noted, Christianity has steadily evolved since the 13th or 14th century. Islam is incapable of similar evolution since the very act of questioning that which is in the quran requires that the questioner be put to death as an infidel.
Crusader Rabbit