ichthys

thumb|237px|Ichthys was adopted as a Christian symbolism|Christian symbol. The ichthys or ichthus (; from ancient Greek , "fish") is, in its modern rendition, a symbol consisting of two intersecting arcs, the right ends extending beyond the meeting point so as to resemble the profile of a fish. It has been speculated that the symbol was used by early Christians as a secret symbol: a shibboleth to determine if another was indeed Christian. It is now known colloquially as the "Jesus fish". This symbol is widely used by Christians as a sign of their faith, often being found on vehicles, necklaces and laptop stickers.

==Origin== thumb|right|375px|An early circular ichthys symbol, created by combining the Greek letters ΙΧΘΥΣ, Ephesus. The first appearances of the ichthys in Christian art and literature dates to the 2nd century. The symbol's use among Christians had become popular by the late 2nd century, and its use spread widely in the 3rd and 4th centuries. In early Christian history, the ichthys symbol held "the most sacred significance". It has been claimed that Christians used it to recognize churches and other believers during a time when they faced persecution in the Roman Empire. Augustine, a Church Father, stated that a fish symbolized Jesus well, writing that "he was able to live [...] without sin in the abyss of this mortality as in the depth of waters". Additionally, the ichthys symbol references the sacraments of Baptism and Communion. With respect to baptism, Tertullian, an early Christian writer, "taught that just as water sustains fish, 'We, little fishes, after the image of our Ichthys, Jesus Christ, are born in the water'". For the "Holy Eucharist, with which the miracle of the multiplication of the loaves and fishes had such intimate connection both in point of time and significance".