But this doesn't happen if you define religion like most people: the belief in and worship of god or gods. Sure we like to throw around the word religion to mean anything from being a devout soccer fan to obsessively following the stock market, but these aren't technical uses of the word. When we define secularism as a religion, its own definition becomes "a religion to separate religion, from religion." Since this makes no logical sense, the theist who defines secularism as a religion creates his own problem for him. Then he complains of governmental favoritism.
Since Christianity already has enough of its own internal contradictions, Christians shouldn't be defining religion in ways that create even more problems for them.