I like Lisa's answer. I, too, approve almost any comment, most of the time. If a commentor has been offensive personally, or threatening, which I have not experienced tho' some say they have, then I would delete that and not give them an audience through my hub for their venom.
I think writing an article implies that you're open to differences, yet sometimes we find out that isn't true with some hubbers. For the most part, comments are "received" if not "well received."
As Lisa says, the freedom of speech is not automatically given by all authors, as is their right.
Endless disagreement and debate can be tiring and brings about no good purpose...sort of resembling how our Congress behaves, come to think of it.
My tip? Write on, and let others comment, as long as they're basically respectful. And, if your comment is deleated, as one or two of mine have been, just chalk it up to experience and move on. Some people go into the kitchen but they can't take the heat.
I avoid commenting on most religious hubs for that very reason. They preach to the choir and woe unto anyone who sees life differently. It's their right, as is mine to ignore it.
Have fun, Hubpages is a great neighborhood, and the "quirks" just give us Pizazzz!