On the back of my car, I have a Darwin fish. I'm sure you've seen them. It's like the Christian fish symbol, but with the word "Darwin" inside, and legs under its body. There are lots of parodies of the Christian fish, and even a few "comebacks" from the Christian side, like the Christian fish with the word "Truth" inside, eating a Darwin fish.
The whole thing is just getting ridiculous, really, but my wife wondered aloud recently as to why there was such a proliferation of Christian fish symbols on cars in the first place, prompting the parodies.
My answer, which I'm sure many will find a bit too glib, is that many Christians have this deep-seated need to advertise their religion. It's no different than those Christians who wear crucifix earrings. It serves no purpose other than to show off one's beliefs.
Let's face it, you can't see the fish on the back of your car unless you're standing behind it. Nor can you see your crucifix lobe ornaments unless you're looking in a mirror. But others can see these things quite clearly.
Theists in general, as I've said before, are insecure at heart. About everything. They need others to see that they have these particular beliefs. It makes them feel better, knowing that others are aware of their beliefs. And of course, the insecurity is what causes them to need the beliefs in the first place, too.
