DP and I are both atheists.
To be honest, I'd be a bit disappointed if either of our children grew up to be religious. I guess I'd feel that I hadn't managed to instill in them enough of a belief in and respect for the importance of evidence and reason. I do and always will challenge my children's views, as I believe that vigorously challenging all beliefs and assumptions is essential for improving and refining our worldviews.
That said, I completely accept that my children's' beliefs and life choices will be up to them; not me. If they come to think differently from me on this matter, then so be it. They'll have my love and support regardless.