religion has been a vehicle for philosophy, and in this regard it has been useful to teach some good things about some basic morality, some good concepts (dont kill, dont get laid with your neighbor wife etc) but it could've been done without the need of religion.
So, even it has been useful, it was not completely necessary or the only way to do so...
You don't need religion to be good. It make some people to be good, yes, but it was not the only way. And looking at the whole picture, for me, it did and still does much more bad tan good.
And it's completely irrational, absurd, without any scientific base and it tends to interfere in individuals lives and liberties.
We would be much better without it.