The Christian cross, seen as a representation of the instrument of the crucifixion of Jesus, is the best-known symbol of Christianity. It is related to the crucifix (a cross that includes a usually three-dimensional representation of Jesus' body) and to the more general family of cross symbols.
The basic forms of the cross are the Latin cross (✝) and the Greek cross (✚), with numerous variants used in heraldry and in various confessional contexts.
The cross-shaped sign, represented in its simplest form by a crossing of two lines at right angles, greatly predates the introduction of Christianity, in both East and West. It goes back to a very remote period of human civilization. It is supposed to have been used not just for its ornamental value, but also with religious significance. It may have represented the apparatus used in kindling fire, and thus as the symbol of sacred fire or as a symbol of the sun, denoting its daily rotation. It has also been interpreted as the mystic representation of lightning or of the god of the tempest, or the emblem of the Aryan pantheon and the primitive Aryan civilization.
Another associated symbol is the ansated cross (ankh or crux ansata) used in ancient Egypt. It was often depicted in the hands of the goddess Sekhmet, and as a hieroglyphic sign of life or of the living. Egyptian Christians (Copts) adopted it as the emblem of the cross. In his book, The Worship of the Dead, Colonel J. Garnier wrote: "The cross in the form of the 'Crux Ansata' ... was carried in the hands of the Egyptian priests and Pontiff kings as the symbol of their authority as priests of the Sun god and was called 'the Sign of Life'."
Another Egyptian symbol is the Ndj (Cross-ndj (hieroglyph)) - Uses for the hieroglyph: 1— "to protect, guard, avenge", and "protector, advocate, avenger" 2— "homage to thee", (a form of salutation to gods) 3— "discuss a matter with someone", "to converse", "to take counsel". Yet another Egyptian symbol is the nfr - meaning: beauty or perfect.