England was Protestant in the majority and the support given by James II was seen as a threat. Also, we can't forget that the Parliament was Protestant and the king didn't receive a response and aid. Because of that, James II usually acted against the Parliament and by his own methods, creating conflicts and disagreements between the parts.
It is important because they are in hiding and if they are to be found they will go to concentration camp and eventually be killed so c the families are in hiding etc