Jesus teachings - which, toghether with 10 commandments, are basis of Christian religion, can't justify killing a man, even of different religion, let alone starting a war. This is the same case for most widespread religions, which have strong moral guideliness.
As with every other belief and/or moral guideline, many wars were justified by misinterpretation of religion. Same can be said for things like patriotism, freedom, free market or human rights, which are non-religious moral guideliness, yet many times they were justified cause to start a war. So, saying that there would be a lot less wars without religion is chidlish.
As for science and scientific progress, that was often very tied to religion throught history, so I'm not so sure about being a super advanced civilisation.
And one can easily compare science to religion. If something cannot be scientifically proven in the scientifically driven society, it is considered wrong or marked as impossible or non-existant. Therefore, if something doesn't comply to the certain set of rules or beliefs (in this case the scientific method), the scientific community is quick to oppose it's validity. That reminds me a lot of Galileo Galilei and theory of heliocentrism, can you see the the connection?
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