by Dr. Robert D. Luginbill
The fish, Greek ichthys
a symbol for Christ which has been in use since the days of the early church. In
Greek, it is an acronym for Jesus Christ, the Son of
God, our Savior:
The origin of this acronym is something else again. It is not in the Bible. No one really knows who first came up with the acronym ICHTHYS standing for the Greek words meaning "Jesus Christ, Son of God, [our] Savior", but probably none of the apostles ever heard of it. We have some representations of the fish in the catacombs as a Christian symbol (see the link: "The Origin of the Name 'Christian'"), but never with any clear indication that it has the meaning above (the early work "The Shepherd of Hermes" also uses the fish). The Oxford Dictionary of the Christian Church posits the 2nd Cent. A.D. as the time when this acronym first came into common use, but opinions are divided. Of one thing we may be fairly sure: early Christians - as we do or should do - sought to share their faith in Jesus Christ. They did not try to hide the gospel "under a bushel". The idea that Christianity was a "secret society" and that members communicated by secret signs with the fish being one such has no basis in historical fact. Indeed, all we know about martyrdom in the early Church (see the link) suggests exactly the opposite: believers of that day were willing to give their lives for the truth in which they had placed their faith. They were not ashamed of being Christians and they did not feel any compunction to hide the fact.
You may also find the following links useful:
Christology: the Study of Jesus Christ.
Soteriology: the Study of Salvation
Church: The Biblical Ideal versus the Contemporary Reality.
Red Hot or Lukewarm? Bible Teaching versus Sermonizing.
The Seven Churches of Revelation: A Historical Map for the Church Age