text: Are they very gnostic believers? If so, of course it's not going to be very fun for them to hear that. Maybe just let it be until it comes up a little more naturally in conversation. As far as I know in the Christian religion the role of the parents are to teach and practice with their kids under the church until they are "adults in the church" and that's all they can do. I'm not sure if there is a similar thing in the Muslim faith, but all you can do is tell them your opinions and there isn't really anything they can do to change that.