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. While attending and participating in religious services gives a good grounding, there is more that adults should do.
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. Parents have to be able to do what I call 'God talk' with their children - that is, talk about God and spiritual things, even with very little children. 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.