I'm not saying it's "more offensive," just that it would be equally offensive to someone of the opposing viewpoint as you.
Moreover, being offended at someone expressing their beliefs is a ridiculous concept in itself. I'm not saying either one of you should change your signatures, because you're each expressing your beliefs and opinions, but being offended by someone doing so is rather intolerant. And, after all, isn't intolerance at least partly a product of religious fundamentalism?
Not to mention it's rather shitty and hypocritical to say you're offended by something, then retaliate by trying to offend that person the same way he apparently offended you.
Now we should probably stop derailing this thread (which I'll freely admit was my fault since I brought up your page-old post).