I've said it before, and I'm sure I'll say it again: It is easy to support free speech as long as one is talking about one's own speech or about the expression of ideas with which one agrees. When we agree with the content of the speech, we are quick to recognize the importance of free speech. We even seem eager to defend it.
The test - perhaps the only test that matters here - is whether one defends the expression of ideas with which one disagrees. When we find someone who claims to defend free speech but is willing to extend his or her defense only to the expression of ideas with which he or she agrees, we do not have a free speech advocate; we have a hypocrite.
It isn't that we must all be free speech absolutists in order to avoid charges of hypocrisy. We can - and most of us do - recognize that a few restrictions on free speech are probably necessary. We must strive to be consistent in our application of any necessary restrictions, and we must recognize that such restrictions require a rationale that goes well beyond our personal offense taking and hurt feelings. It isn't always going to be easy, but that does not make it any less important.
Criticism of religious figures, traditions, and beliefs is a vital form of free speech. Criticism of secular figures, traditions, and beliefs is a vital form of free speech. We do not all have to like both equally, but we do need to allow both. Any suggestion that faith is exempt from inquiry, criticism, or even mockery is dangerous. We all lose when the expression of dissenting ideas is suppressed. And the same is true when it comes to the inquiry, criticism, and mockery of atheism, secularism, humanism, skepticism, and feminism. If their cows are not sacred, ours are not either.
At the risk of being overly repetitive, I'll leave you with the following: Our commitment to free speech is not found in our willingness to defend the expression of our most cherished ideas; it lies in our defense of the right of others to express ideas we find abhorrent.
For more on this important subject, see Samantha Clark's post at Jill of all Trades.
Update: Post edited to improve clarity based on an excellent suggestion by a commenter.