In my fonética class (phonetics), we read a story entitled ICTUS. It told how many of the towns and countries in new testament times spoke different languages. For commerce and general exchange of information, the common language was Greek; hence the disciples preached, taught and wrote in Greek.
As it turns out, the phrase Jesus Christ, Son of God, Savior, in Greek appears as Iesous Cristos Teou Uio Soter. The first letter from each word, in Greek letters are: ἰχθύς (Iota Chi Theta Upsilon Sigma), or with our alphabet: ICHTHUS. (The χ and the θ are represented by CH and TH.) ICHTHUS is the Greek word for fish! How cool is that?
But wait, there’s more…
The fish symbol was intentionally a very simple design: two opposing arcs connected in a point on one side and overlapping on the other side. Not only was this symbol used to indicate Christian meeting places and decorate artifacts, it was also used to secretly identify other believers. If after speaking with someone, instead of coming right out and asking if they were a believer (which could get you in trouble if you asked the wrong person!) one person would draw the top arc. The other person would either ignore what you did, not understanding what you meant, or draw the bottom arc, completing the fish symbol. If that happened, you would each then know that each of you were believers!
Think about that next time you see the fish symbol!