The Greek word for fish is ichthys. Early Christians made an acronym from this phrase: Iesous Christos Theou Yios Soter. This means Jesus Christ, Son of God, Savior. When early Christians were being persecuted, the fish became a secret symbol among them. The image of the fish continues to be a symbol of Christianity today, even to the point of sparking a bumper sticker fad in the 1990s. The fish symbol on bumper stickers spread to other things, such as key chains, T-shirts, and jewelry.