Mixed marriage has been an historical "no-no" in Judaism as essentially it would dilute Jewishness.
Religion is used to maintain the tribe.
It has been said, "Jesus played with the children and challenged the adults."  The Roman Church's catechesis has been to challenge children and play with the adults.
Ignatius of Loyola and Lenin both contended getting the child at an early age and controlling them for life.  Their worlds largely has changed in the present.  
Indoctrination of children can be a form of abuse, especially when pounding into them a "theology" of fear. 
As an evangelical noted, "God has no grandchildren."  Conversion to Kingdom values should be an adult decision.  True values are caught, not taught.