Pickle, first, I want to be upfront that this 'advice/idea' is coming from a non-religious person. However, it's applicable for pretty much any situation.
My take is that you cannot control the thoughts, ideas or actions of anyone, especially (X)W. No matter what your D agreement says, that is a very hard boundary to enforce.
I understand how important it is to you for both you and your kids. My assumption is that your kids have been a part of the church most if not all their lives. Given this, and given that they will at some point leave the house for their own lives, I think it might be best to be encouraging but let them figure it out for themselves (at least D17). I think that if you try to force the issue, it will be more disrupting than your current sitch. If you've set a good example, I think things will work out well.
It's a thorny issue and I wish you luck with it.
Oh, I think it's spelled 'dos' by the way
Me 43 W 38 M 5 T 7 SD20 S15, S13 with 1st W ILYBNILWY June 2010 Separation/Bomb July 2010 Divorce Feb 8, 2011