Latin and Greek letters, words and abbreviations are often seen in Christian art. Though not exactly symbols, they are intended to convey a particular meaning significant for Christians.
Alpha and omega are the first and last letters of the Greek alphabet, signifying that Jesus is "the beginning and the end," i.e., eternal. (Rev 1:8)
The Chi Rho is a symbol made from the first two letters of "Christ" in Greek. It is said that before an important battle, the Emperor Constantine saw this symbol in the sky and heard the words "By this sign, conquer."
Ecce homo means "Behold the man," which was said by Pilate before Christ's crucifixion.
Ecce agnus Dei is Latin for "Behold the Lamb of God." This phrase is used during Epiphany, which celebrates Christ's manifestation.
INRI is the Latin abbreviation for "Jesus Christ, King of the Jews," the sign placed above Jesus' head on the cross(John 19:19) Though the sign was intended to mock Jesus, Christians view the phrase as a confession of faith.
IXθYΣ or ICHTHUS is the Greek word for "fish" and an acrostic for "Jesus Christ, God's Son, Savior." See Christian Fish Symbol for more information.
IHC or IHS is the first three letters of the Greek word for "Jesus" (iota, eta, sigma).
