The Relationship Between Christianity and Islam

After doing a lot of thinking, I've come up with a hypothesis of sorts. What if Christianity and Islam are on the same development path? What I mean is that Christianity and Islam are so closely related, that I believe their societies have evolved along a similar pattern. Here's why I think that.

Christianity is roughly 600 years older than Islam. Christ died somewhere around the year 33 AD, and Mohammed in 632 AD. So, in that sense, Christianity is 600 years "more advanced" (I mean that lightly, of course) than Islam.

Islam right now is in a very violent state. It discriminates against women, condemns blasphemers, and reacts violently to change. It's no wonder that many of the middle eastern states are theocracies, ruled entirely by their Ayatollah's and the like.

But, may I ask, what was Christianity like 600 years ago?

The Christians of the 15th century were much different than the ones we see today. They were violent, condemned blasphemers, discriminated against women, etc. See a correlation?

My theory is that because Islam is 600 years younger than Christianity, it is simply 600 years behind in the development. Islam is now just as violent and wacko as Christianity was 600 years ago. This is demonstrated, as I said, by the similarities between the cultures in their respective times. Islam had a period of mass expansion, so did Christianity. Christianity is (relatively speaking) peaceful at the moment, and that may just be that Christianity has had 600 years of a headstart.

The problem with Islam may not be that it is naturally a violent religion. It is just as peaceful as Christianity (or at least, as peaceful as it was intended). The issue here is that Islam is at a point in its development where it is getting extremely fundamentalist (like 15th century Christians). Those violent interpretations of the holy books are something that is shared by both religions, and we interpret that to mean that Islam is violent and dangerous as a whole.

I wish this comparison worked with all religions, but I don't think it would. Societies are too different to compare, say, the Hindus and the Buddhists. That is all.