Why are Christians against evolution?

[Darwinian]

As much as there are scientists who support evolution, there are as many scientists who don’t support it.

Because, I suspect, they are not evolutionary scientists or serious scientists but instead those who work in broadly based scientific fields and they, like you, are religiously brainwashed and would rather believe ancient fairy stories written down by those who seek to control through fear and superstition rather than the facts gathered by their intellectual superiors over many, many years.

so if evolution was a fact then it will be an established scientific fact and everybody would agree.

Is is a well established fact and everyone who has studied it with an open mind does agree. Except of course for those who desperately don't want to believe because it would contradict their faith and so they, metaphorically, shut their eyes, stick their fingers in their ears and shout "I'm not listening!"