How is it a stable life to see your mother eating cheeseburgers and your father learning gemara?? I dont understand what you think is stable?
Listen, a kid from a divorced house is going to have some things to deal with even in the best of scenerios.
That's his pekelah.
And ideally a parent who changes his/her path still has the child's best interest at heart and plenty of times that means respecting how they were raised until a certain point.
Compromise should always be part of the picture. On both sides. And it won't be perfect no matter what.
But there is still something to be said for a child having a relationship with their mother/father.
You can't write off a parent just because they change their path.
It's not that I don't understand how complicated it can be. And I get not wanting to expose a kid to things but sometimes thats what life throws at you.
You shouldn't lose a child just because you change your path.
If that means becoming not religious.
Or becoming religious.