Those two can and should coexist. Me supporting the rights of a members of a religious groups does not and should not translate to me not being able to offend their religious sensibilities.
In fact, I wholeheartedly oppose blasphemy laws, regardless of the particular religion flavor that they apply to.
They should have the right to go around with their head uncovered and I should have the right to trash-talk their religious idols/gods/priests/what have you.