For as long as the ideas of science and religion have been, there has been tension between them, and even bloodshed over them. Ideas like, "What if the Earth revolves around the Sun?" and "What, if not God, caused everything we know, the universe, to come to be?" have led directly to the deaths, imprisonments, and exiles of many of our greatest minds, and to the temporary loss of their greatest discoveries. When I think about how much history and information was lost due to confrontations with religion, it's depressing. Where would we be right now if instead of condemning scientists, we had embraced their work and seen to it that they had the best resources?
Into The Past
Religion was and is also a political tool, it kept people in check. People in power used religious ideas to control the masses, and to keep themselves in power. Religion has always had a tendency to motivate people to extreme levels, it adds a transcendant level of meaning to things, it gives people an individual purpose. If you had a choice, as a general, to command an army of atheists or an army of religiously motivated people, I bet you'd choose the religious people. Why? Because they'd fight tenaciously, unwaiveringly, because they know that's what god wants them to do, they know that's their purpose in this life. The skeptics on the other hand, would always be questioning, always asking if what they were doing was truly right in the big picture, always asking if the risk was worth it to them.
In the past, so many scientific advances have emerged going against the grain of religion. When he came up with the idea that the Earth was just one of many planets that revolved around the sun, Copernicus' work was seen as defiant of holy scriptures. Anyone who defended the ideas that the Sun did not move, and that the Earth revolved around it was convicted as a heretic. Indeed, Gallileo was placed on life-long house arrest for this very belief. It would seem that religion in the past, has had the upper hand in this "war".
Today and Tomorrow
We're lucky in this age that science no longer takes the backseat to religion. There are no longer book burnings, or people burning at the stake for that matter. In modern times all we have to deal with now are fanatic religious people, small groups when you compare it to large holy empires.
The "war" is still being fought, though, and it will be interesting to see how it pans out. There are Ted Haggards and crazy evangelicals, there are a large number of children being homeschooled by parents, teaching their kids only a small amount of real science, and a large majority of Christian stories. There have been demands that evolution and creationism be taught in public schools as side-by-side theories with equal merit and that equal time be given to both, and while this hasn't yet happened in public schools (to the best of my knowledge), it certainly has happened in some Christian schools. In Kansas you have the Westboro Baptist Church who are infamous for demonstrating their extreme hatred towards gays and others at the funerals of soldiers who, most of the time, aren't even gay. They also protest the funerals of celebrities or high-profile funerals in order to gain noteriety, such as those who died in the shooting of the Arizona senator Gabrielle Giffords, including the 9-year old girl, Christina Taylor Green. So I say that we're lucky, but we do have a long way to go.
Scientism is a somewhat newer word that springs up when people argue science and religion. Scientism refers to a world view or philosophy or ideology revolving around science, or an innappropriate application of the natural sciences to areas of philosophy or whatnot. Most scientists, I think would agree that scientism is a non-sensical word. Science is not a position, it's not a way of life, it's not a philosophy, it's a method by which you discover new things about the real world.
One might ask, "Why can't science and religion just get along?"
Well, I wish they could, but I don't think we'll ever see science and religion "getting along". There will always sort of be a "war" between them, with one group fighting for skepticism and the other fighting for faithful belief. I, for one, would never want to take away someone's belief if it's what keeps them going and provides them strength of will to get through their day. I also wouldn't want my doctor to stop and pray in the middle of giving me surgeory, and I wouldn't want them teaching my kids Christianity in public school science class. I think that in the future what we will see is that there will be a great decrease in religious influence, and a greater appreciation for science and technology. Just maybe in a hundred years or something like that we'll live in a world where we no longer say "Thank God I survived that car accident!" we instead thank the people who invented the airbag and safety belt. Maybe, if science is allowed to flourish, we won't even have to worry about car accidents anymore, or cars for that matter! We shall see.