Removing certain words from public discourse or silencing debate all together is a powerful way to manipulate not only language, but ideas. The civility Voltaire advocated is gone. "Hate speech" has been defined by some groups as ideas with which they disagree.
In a pluralistic society, we must expect to hear some views with which we disagree, and as long as the speech does not incite violence, or diminish the intrinsic dignity of persons should be tolerated in a healthy democratic climate. This includes speech of religious belief and the moral values we hold as a nation.