Sherds of evidence state that the symbol of the cross was used centuries even before Christianity actually formed. The origin dates back to the Babylonians, typically the 11th dynasty of the Kings of Babylon usually referred to as the Chaldean Dynasty or the New Babylonians. The symbol of the Cross prevalent during that time was called the Chaldean cross. The symbol was believed to be the symbol of an ancient Babylonian deity Tammuz, the Accadian Sun God. The Chaldean cross began as a circular sun symbol. Two beams crossed the circle as a representation of the sun's rays. Eventually, the Chaldeans dropped the circle altogether, leaving only the two beams
Later the symbol of the cross was spread to other parts of the world such as Syria, Egypt, Greek, Latin, India, and Mexico with relative modifications. The pre-Christian cross was used as a religious symbol and as an ornament among the Egyptians, Syrians, Greeks, Persians, Europeans, and in some parts of Africa. There were mainly two types of Pre Cristian cross, namely, the tau cross and the swastika or fylfot cross.
The tau cross represents the Greek capital letter T. The Tau Cross started life in Egypt as a pagan symbol. The Egyptian hieroglyph representing life is called the Ankh. The Ankh has the appearance of a tau-type cross topped with a loop. Important figures, such as pharaohs and kings, were often buried kissing the Ankh. It’s believed that ankh preserved immortality or in other words life after death. Even Egyptian Gods such as Osiris, Isis, and Ra are depicted in temples holding the ankh. It could also have a more physical connotation: the ankh may represent water, air, and the sun, which were meant to provide and preserve life in Ancient Egyptian culture.
Fylfot is an old English word which is supposed to be a corruption of the Anglo-Saxon fcower fot, i. e., four-foot. It denotes a peculiar form of an equilateral cross with ends turned which among the Germanic tribes is said to have been sacred to Thor, the thunder- god, and is, therefore, rightly or wrongly, also called the hammer- mark of Thor. The figure is an ancient pagan symbol and is now commonly called by its Sanskrit name swastika. The Sanskrit name "swastika" is derived from “su” well and asti "welfare," or "hail," and may be translated as "a symbol of bliss and salvation."
Evidence of the use of the cross centuries before the coming of Christ can be seen in British Museum on the effigy of King Samsi-Vul of Assyria. Besides, goddess Diana of the ancient Greeks is portrayed with a cross in a way that resembles how Virgin Mary is portrayed in statues by artists.