Why are people saying Christians suck?

EVERYONE at school is saying that Christianity is an obsolete, ancient religion. They say there is little to no point in it and that everyone who worships an archaic religion that apparently ended 150 years ago is 'misled', and cannot prove a God. They also say that Christians are the crux of all disputes and subsequent military conflicts of the last two thousand years. Is this all true? I have no idea, I've never been religious myself. Just curious.