Originally Posted by CatholicCrusader
Good point. I forgot all about that. Were they not using that as some secret recognition signal?
Yes. During the persecution, they used the fish as a secret recognition signal. One Christian would draw a half of the fish on the ground with his finger. If the other person he was speaking to was a Christian, he would complete the fish by drawing the other half. If the person he was speaking to doesn't complete the fish symbol, then that means the person is not a Christian and he need to watch what he says to him.