Religion should always be separated from politics so that ever thing runs smoothly and peacefully. It is sometimes becomes an issue when some leaders makes it an issue and tries to create rift among people through mixing politics with religion...
Not only BJP many parties like congress and even CPM also are mixing religion with politics.That is why some region has special candidates according to the religion of that area.
As our electorate are affected by caste, religion, region considerations, the political parties have no option other than to field candidates considering these aspects. That is why even secular parties field candidates considering religion, caste etc.