If the children choose later to go away from that, that is their choice. But when they are young, they should not have choices with their belief system, because they are your children, they are your responsibility. It's like discipline and eating your broccoli. When you are a child, you have to eat your broccoli. Later you may decide never to eat your broccoli again.
Parents can use mealtimes, bedtime, even when they are riding in the car as teaching times.
Faith has to be home-based, where the primary communication has to happen in the home. There are so many ways to do that. It doesn't have to be separate from normal conversation. Outside of the church, there are many ways in the community, even if it's cleaning up your own neighborhood or volunteering in nursing homes or Scouts, to uplift our brothers and sisters in our community. If I am to build my Christian character, then I have to instill in my children through example by working in the church, community and schools and showing them when God is present in us and gives us a special gift, we ought to use that.