Not all christians go to wars and kill people, not all christians support wars, and killing. Do not blame religion, blame the person. There are bad atheists who kill people, there are also religious fanatics who use religions as a cover up for their selfish motives inside. Men who kill people like to look holy so religion is a good way to kill and look holy at the same time.
If you look at the early christians, as in, the christians that are first generation christians like Paul, etc. They generally do not go around killing people, they ended up being the one who is killed. They do not preach killing people. Jesus Himself does not resist His arrest, and refuses to get into political agenda with the people around His time.
Jesus tells Peter to put away His sword when the roman soldiers are about to arrest Him. In one instance, Jesus' followers want to make Him a King but Jesus chooses to flee away from them, instead. He is not interested in the Jewish movement of His time, the general feelings among the Jews to overthrow the roman empire.
Paul teaches slaves to submit to authorities, to their masters, to do their labors faithfully, to suffer for doing good rather than evil. This is a kind of "I rather be trampled on by people than trample people" teaching. It is a kind of "I rather let people be moved by my loving kindness and submission than repay evil with evil" kind of teaching. It is a "Do not repay an eye for an eye, a ear for a ear" kind of teaching.
So, the early christians do not fight through killing people but through loving the enemies even when being killed by them, it is the later part when suddenly, everything just changes.
And that is not surprizing.
Ambitious people will use anything to achieve ambitious things, including religion. Some ambitious people who use religion may not even truly believe in their religions. They use it merely to deceive gullible followers.
Example: If Osama Bin Laden is so religious until he is so concerned about not working with infidels, why did he work together with America's CIA for awhile until things turned against him?
For people with political or other ambitious motives, getting their goal is what matters. They may not be religious, they may not believe in a god or any god, but they will pretend to be a christian, a muslim and everything in order to add one more tool to their advantage... religion.
You see, men who are in power, who want more power, will use anything to get more power. And religion is a good way to do that. However, it is not religion that is at fault, but rather the one who uses it wrongly.
If there is no religion in this world, the wars, the terrorism will still have happened, under different names.
Therefore, a christian can be someone who use christianity for his agenda, or someone who changes himself to be a better christian. A muslim can be someone who uses his religion for political gain, and someone who changes his political agenda to be a better muslim.
Religion is not the thing. The heart of the one who fights is really the thing.
