About the symbol: The cross, the common method of Roman execution, upon which Jesus was put to death as God's price and payment for the salvation of all the peoples of the earth who believe.
Christians proclaim that only by faith in The Christ, being the Son of God and second person of the Trinity who existed before Creation, can people be reconciled with God the Father. This Christ, who became human in the person of Jesus of Nazareth, is the only savior who can open the door to salvation for all humans. This salvation is mandatory since every child is born hopelessly sinful. Without this faith in The Christ, unbelievers will be doomed to an eternal damnation and torment away from God's presence in hell.
Christianity, stemming primarily out of an aberrant sect(the Essenes)of Judaism and developing widely in the West, has become the largest religion of the world even though it is the 3rd youngest major world religion. Approximately one in every three persons on earth is identified in some way with Christianity. Millions worship in their native religion while sharing in the appropriate Christian services.
A religion practiced by so many people naturally encompasses an immense variety of beliefs and practices from the silent worship by the Quakers to the snake handlers of the southern Appalachians, and the staid formality of the Catholic & Eastern orthodox churches. During its growth, it has incorporated vast quantities of religious beliefs from other religions; Phoenician, Greek, Zoroastrian, Babylonian and those that are earth-centered.
The creed of all Christians is that Jesus is Lord and Savior.