For me the Christians who follow religion and don't have to reject at least some science aren't proper Christians. I'm not saying all Christians have to be creationists, but the fact exists that there is no real room in scientific theory for God to exist. "We just haven't discovered him yet" is not a valid argument, because there's plenty of crap we'll never discover simply because they
don't exist. We've not discovered monkeys with 13,000 fingers. We've not discovered whales the size of Jupiter. Sure, we've not discovered aliens either, but their probability of existence is at least roughly on a par with ours, and we know we exist (stfu Philosophy

), therefore their existence isn't hugely unlikely.
The people who follow science yet still claim to be Christian aren't proper Christians. They're the sort of people who don't read the Bible, don't go to church, don't really lead any sort of religious life aside from the fact they say they're Christians. They're the people who 'believe' in God purely out of convenience. Not much thought involved, just the fact that it's probably nicer if he does exist and if they say they believe him. They're basically just agnostics claiming to be Christians, not really too different from people who claim to be Christian purely through the argument of Pascal's Wager.
I'd argue that the world would be a better place if all organised religion was destroyed. I wouldn't go to make outlandish claims that we'd live in some sort of Utopia where there were no wars and everyone lived happily, but I do think it would be better.
There would still probably be wars. We'd find other shit to fight about. But at least the wars would make a little more sense. We'd have acts of terrorism and wars based on proper issues, such as imbalance of wealth, power, land. Wars formed over true injustices, rather than religious wars simply because their made-up God isn't the same as our made-up one. Ideally I wouldn't want any wars, but if you're going to fight about something you might as well pick something worth fighting about.
Organised religion also has a shitload of money locked up. In America alone the Catholic Church has enough wealth to buy out all of the richest dozen or so corporations (combined). It's insane how many trillions of dollars that is owned by religious bodies, and how much benefit that money could otherwise do were it not locked up in people's beliefs. We could eradicate poverty in Africa, remove our dependence on coal and oil and convert ourselves to use renewable energy sources. Heck, we might even have some money left over to find cures for Cancer and AIDS. If we could strip that money from religion and distribute it properly, I don't see how the world couldn't be a far better place for the global population.
The main argument (that I've heard at least) for retaining religion is that on an individual level it helps people. It helps people find some sort of solace when they're troubled. It helps bring them back from the brink of suicide. Perhaps a fair argument, but really I don't see that all that won't still happen without religion, because I find it depends more on your mental outlook.
If your mother goes crazy and tries to kill you as a child, but fails, then you could say that God saved you, and find some sort of peace in that. On the other hand, you could say that for some reason God tried to kill you, and random chance prevented it from happening (though this fails a little under the illusion that God is both omnipotent and not evil). I'd say that if God was going to save you, why the fuck would he let you have the trouble of nearly dying? There was an assassination attempt on the Pope a while ago, and he got shot. He said it was an act of God (I think it was the Virgin Mary more precisely) that the bullet intended for his heart was strayed away and the wound was non-fatal. But if that was the case why wouldn't they have gone the full measure and stopped it hitting him completely. Why not make the gun malfunction and explode, wounding the assassin. That'd be a proper miracle, rather than the more plausible explanation that the assassin had crappy aim, due to not being professionally trained in any way to use firearms, and simply missed.
When people are troubled, they should be able to find some way to bring themselves up if they're so inclined. There's no reason why they should need religion, or why religion can do something that nothing else can't. We don't need it for morals or for support - society does a perfectly good of providing that now.
Religion is disappearing. In Europe it's moved out to a decent extent, with most people at least being agnostic or weakly Christian. People who are devoutly religious are getting extremely rare as most people accept the more logical and proven scientific alternatives over more implausible religious beliefs that require blind faith as they have little to back them up. Most people who go to church now are pensioners with little better to do on a Sunday and who are more ingrained to the older religious beliefs. Or they're just aware that they're closer to death and are trying to perhaps make amends before they go.
America seems to be more heavily religious and more resistant to change, but I still can't see it holding out for much longer. With each generation it'll continue to slide. Whether the world is better off or not as a result, it won't be long before religion falls altogether and Christianity is viewed as somewhat delusional in the same light as ghosts, alien abductions and telepathy.