Latin Cross (Christian Cross)

The most well known cross is the Latin cross, which to Christians, represents the cross of Christ’s crucifixion. When shown with the image of Christ, it is called a crucifix.
The shape of a true Latin cross, when folded, creates a cube, an ancient symbol of earthly authority. 

The cross of Christianity was a later symbol of the faith, replacing the lamb, fish, alpha/omega, and phoenix as emblems. It was previously considered a pagan symbol, with several early church fathers objecting to its use. 

Wrote Christian father Minucius Felix, “You certainly, who worship wooden gods, are the most likely people to adore wooden crosses, as being parts with the same substance as your deities. For what else are your ensigns, flags, and standards but crosses gilt and purified? Your victorious trophies not only represent a simple cross, but a cross with a man upon it. When a pure worshiper adores the true God with hands extended, he makes the figure of a cross. Thus you see that the sign of the cross has either some foundation in Nature, or in your own religion, and therefore not to be objected against Christians.” 

The original Christian cross, today called the Greek cross, is shaped like an X. The Greek Cross was an abbreviation of the name “Christ,” not a representation of the cross of the crucifixion. The Chi-Ro monogram of Constantine is closely related to this symbol. The latin cross came into favor later, when the mother of Constantine, the Empress Helena, claimed to have discovered the “true cross” of the crucifixion, the beginning of an endless trade in holy ‘relics.’
Some crosses of various Christian Churches are variants of the Latin cross: