The Cross is the main symbol of the Christian religion. It is used as a reminder of the crucifixion of Jesus Christ on the wooden cross, who is thought to have died for the people’s sins. The cross is therefore a sign of both Christ himself and the faith of the Christians. There are actually four different versions of the cross. The Greek cross, crux quadrata, has four equal length arms; the Latin cross, crux commissa, the base stem is longer than the other three arms; the Roman cross, crux decussata; and the crux immissa. Most believe that Christ died on the crux immissa, however, some believe that it was a crux commissa. Before the time of the emperor Constantine in the 4th century, Christians did not openly portray the symbol of the cross, as they feared it would expose them to ridicule or danger. After Constantine converted to Christianity however, he heavily promoted the cross as a symbol of the Christian faith. Many crosses are painted with a depiction of Jesus Christ on them. These depictions vary across time periods and religious sects. Churches often also have an ornamental cross on the top of the building.
(Encyclopedia Britannica)
