In Christianity, the inverted Latin cross is a symbol of human humility and unworthiness compared to Jesus. In modern times, the symbol has also taken on an anti-Christian meaning to some, demonstrating complete opposition to the religion by inverting its primary symbol.
The inverted cross, called St. Peter's cross, originates in a story from the apocryphal Acts of Peter written near the end of the 2nd century. The story describes the martyrdom of the apostle Peter, saint and official founder of the Catholic Church. The text asserts that the long-deceased Christ instructed Peter in a vision to allow himself to be crucified. Peter assented, but requested to be crucified upside down, as he saw himself as undeserving of death in the likeness of his Lord.