Daniel,
All things, they tell us, teach us Christ's suffering. I ache for and with you, especially over your grandchild, but as they also say, GOD's IN CHARGE...not your misguided son.
Seeds have been sewn. Live your faith and be a beacon to both him and your granddaughter!
We win more people by example the proselytizing!
I fall far short of both I'm afraid, but I offer that as encouragement, not admonishment...
Keep the Son in your eyes!