How should decisions about religious law be regarded by civil legal systemThe legal system based on Sharia.

I think that the answers you develop here should merely serve
as  a prologue to further research and thought about the topic.  The concept of the sharia is
going to be something that requires depth and delving into thought.  I think that the question
makes the assumption that the civil legal system is separate from the religious one.  In the
Sharia conception of justice, it seems that the latter envelops the former.  The presence of
Islamic tenets and beliefs envelop the civil law setting.  Unlike other Western forms of
jurisprudence where religion stops short of the civil setting, Sharia demands that the legal
system is to be fit around the premise of the religion.  Religious laws are the only laws. 
Having said this, the link below features different examples where one really sees the strong
presence of civil law ideas within the religious one.  In the end, the law of Sharia compels one
to believe that religion is the force that regards the civil law system, and not the other way
around.