Speaking to children about spirituality

I am 36 years old and I’m a single mother of two children (girl 16 and boy 7). Although I’m still in the process of learning, right now I consider that I have actually reached a higher level of consciousness, based on what I knew 7 years ago.  I feel the need of helping my children to become aware of the difference between religion and spiritual awareness/enlightenment… please excuse my grammar, I’m from Venezuela and my English is not that good, I hope that I’m expressing exactly what I mean to ask…

My daughter is often invited by her friends to go to church, most of them being from the Christian denomination.  I don’t believe in religion/church as an institution. I’d like to know what is the best way to start introducing children to our believes? It is hard for me because I don’t belong to any church. It’s hard to talk about God to them, because my opinion differs from what they often hear outside. My seven year old boy, goes to a Christian church during his dad’s visitation.  Could you give me an advice?