How to put this gently...

"Since when is the Hebrew Bible not a part of the bible used by Christians?"

Ah, but used for what, dear boy? For Christians, the Old Testament represents a philosophical and historical basis for the ministry of Christ. It provides his prophetic credentials, if you will. However, for Christians, the history of the Jews is just that, history. We are not Jews who suddenly saw the light, we are the progeny of the Gentiles to whom Paul and Timothy and Luke brought the Gospel. The teachings and fundamentals of Christianity do not reside in the Old Testament. In fact, the early Gentile Christians didn't use it and weren't familiar with it.

"If it is irrelevant, then there should be no argument by Christians for opposing gay-marriage, we should disregard all Ten Commandments, etc."

My, my. Don't we have a broad brush today? No thinking Christian bases their opposition to homosexuality or their support for the Ten Commandments on the Old Testament. We're Christians, we're not Jews.

"Fundamentalism is a disease on all religions..."

And that brush just keeps getting broader. Fundamentalism, of itself is not evil or problematic in any way. It is the application of fundamentalism that becomes troublesome. That's why the mainstream media's continual representation of the Muslim terrorists as fundamentalists is so annoying. Yes, they're fundamentalists, but the fundamentals of Islam are violent and abhorrent. That appellation would make one think that fundamentalists of any religion are dangerous psychopaths. Have you ever encountered a fundamentalist Buddhist? They are hardly warlike creatures. And I certainly don't see the denizens of Brown Mountain building pipe bombs and hijacking aircraft, yet the vast majority of them are as fundamentalist as it comes.

"So, over the last several centuries Islam moved from being a progressive religion..."

Pure fantasy. Islam was never a progressive religion. The Arabs had a very progressive society during the late middle ages and early renaissance, but that term applied only to their scientific and mathematical accomplishments. Their society was still based on warlike conquest, sharia, and a convert-or-die policy.

"...Islam was much more a proponent of women's' rights in the 1300's than was Christianity; and more then than it is now..."

More fantasy. Women have always been considered chattel in Arabic and Islamic cultures. You cannot offer evidence to the contrary. The only rights women have in Islam is the right to choose between the brown burqa and the black burqa. I'd like to throw out at this point that the history of the world as told by Graham Flynt is fraught with danger for those who would debate on the basis of actual facts.

"Throughout American history Christianity has seen a relatively steady decline in the number of churchgoers -this decline became even more rapid during the 20th century."

I'm not sure what this has to do with what we were discussing. So what?

"As a result of this perceived, or very real, threat against the religion, fundamentalism in Christianity is on a sharp incline. (We are actually debating evolution vs. Creationism again.)"

Man, you rode your bicycle off into the weeds with that one! Let me see if I have this correct. People stopped going to church in America so that caused more people to become fundamentalists. I'm sure that makes sense in some twisted corner of liberal dementia, but I'm at a loss to find any objective logic in it. I can't quote any relevant statistic on it, but I'd bet real money that fundamentalism as a percentage of the population of both Christianity and America is probably less now than it ever has been. And the debate around creationism and evolution has never stopped since Darwin proposed it, so I can't imagine what you mean by "again."

"If reasonable Christians don't want to walk down the treacherous path of fundamentalism..."

I don't think we have definitively established that fundamentalism represents a "treacherous path."

"...church leaders should not focus on social mores taught in the Hebrew bible (aka the OLD TESTAMENT), but instead focus on the New Testament (and what Jesus SAID as opposed to who he was)."

Well now, I can't comment on what they teach at the churches you have attended, but in the dozens and dozens (I'm not exaggerating) of Christian churches I have attended, that is exactly what they do. Not to be an old stick-in-the-mud, but you kind of wandered off-topic here as well. You have deviated into a discussion of Christian morality. We were discussing whether Islam teaches violence and if there is a parallel in Christianity. Not the same thing.

Your argument is that the real problem is fundamentalism. That is the argument of the Islamic apologist. There is nothing in the direct teaching of Jesus that allows Christians to go out and kill infidels (or anyone else for that matter). In fact there are numerous and very strong prohibitions against it throughout said teachings. The same cannot be said of Islam. Both in the personal life of Mohammed and in what he wrote in the Quran, there is ample direction to Muslims that the killing of infidels and the barbarity of sharia were and are his express wishes. There is no ambiguity. Fundamentalist Christians absolutely may not participate in these behaviors. Fundamentalist Muslims have no choice but to participate. There is the difference.