Why is the FISH a symbol of Christianity?
The symbol of a fish was found on ancient Christian monuments and buildings. It represents Christ.
The Greek word for “fish” is ICHTHUS.
If we take the letters of that word they provide the first letters of other Greek words.
Iesous Christos Theou Uios Soter
Jesus Christ, Son of God, Saviour
So the symbol of the fish suggests all this to a Christian. It may well have been a secret sign used by early Christians to identify each other.