There seem to be at least two things going on here.
You seem to think a religions age is somehow determine to how violent it is. As if it has stages to go through. While there might be parallels you can draw you basically debunk this with your own claim about how Mormonism was born post enlightenment.
Second, we seem to mean different things when we talk about what Christianity is or what Islam is.
I can't make any comparison to the Christians today and the Christians from the 1600s. Why? Because the societies they have lived in are so different.
There was a period of time when Islam was very enlightened and interested in learning and advancement.
Those times are gone.
Christianity has gone through many epochs too. But it has lost so much power because of the textual criticism of its holy books, the same book that inspired Europe to burn witches today inspires soccer moms to get pissed when the teacher talks about evolution.
No where on Earth right now to my knowledge are there large groups of Christians wanting to kill people for lifestyle choices.
In living memory, Christians have fought each other over what type of Christian they were, but these aren't purely religious divisions.
Man, if you can't see that modern Islam and modern Christianity present two entirely different types of problems you're blind.
If you ask me, could the bible or the quoran both inspire violence at about an equal rate. I say yes. But Christianity isnt just the book and neither is Islam. They're also the societies in which they live.
They evolve through time. Right now, Christians aren't committing atrocious acts en mass. Even in recent flareups like northern Ireland, the worst days there were a calm day in Syria today.
Christianity and Islam neither exist in a vacuum. They have to be examined in the societies they live in.
