I'm a catholic and I teach my kids about all religions. I explain that some people believe different things and some people don't believe at all. I tell them what the Bible says about creation and what science says.
I tell them what my personal beliefs are but I encourage them to make their own minds up. I answer questions with "well this is what I believe but you might think something different".
I take them to Church and they know about the religion we follow, but I do encourage questions as far as I can bearing in mind their young ages.
So what I say to you is this. Don't put a barrier between yourselves and religion when it comes to your kids. Arm them with information and let them make their own minds up. If you push them a certain way, chances are that they'll reject it later on in life. Whereas if you add your support to whatever they decide to believe or not, it will give them the confidence to choose their own paths.
You may be disappointed in their choices but don't try to influence them too strongly one way or the other.
So says me.