The fish is one of the most common symbols of Christianity and faith.
It was used by early Christians as a secret symbol. ΧΘΥΣ (Ichthus) is an backronym/acrostic for "Ίησοῦς Χριστός, Θεοῦ Υἱός, Σωτήρ", (Iēsous Christos, Theou Yios, Sōtēr), which translates into English as "Jesus Christ, Son of God, Saviour":
- Iota (i) is the first letter of Iēsous (Ἰησοῦς), Greek for "Jesus".
- Chi (ch) is the first letter of Christos (Χριστός), Greek for "anointed".
- Theta (th) is the first letter of Theou (Θεοῦ), Greek for "God's", the genitive case of Θεóς, Theos, Greek for "God".
- Upsilon (y) is the first letter of (h)uios[6] (Υἱός), Greek for "Son".
- Sigma (s) is the first letter of sōtēr (Σωτήρ), Greek for "Savior".
Fish are mentioned several times in the Gospels (we may remember that several of the twelve apostles were fishermen, Jesus also multiplies loaves and fish to feed the multitude at the feeding of the five thousand).
The fish is also used by Jesus to describe "the Sign of Jonah". (Matthew 12:38-45) This is symbolic of the resurrection of Christ upon which the entire Christian faith is based. ( 1 Corinthians 15:1-58)