The word "Catholic" is derived from the Greek word for "universal." In its most basic form, to be Catholic means to belong to the universal church, which, in theory, encompasses all of Christianity. However, due to the many schisms that plagued the history of the Christian faith, Roman Catholicism has necessarily developed a more specific meaning.
Roman Catholicism has defined itself as the Christian Church in full communion with the Bishop of Rome, otherwise known as the Pope in the Vatican. It is one of the oldest Christian churches in existence, and currently the largest body of organized religion in the world. It traces its roots to the original church as founded by Jesus Christ.
Like most of Christendom, the cornerstone of Catholic Faith is the Resurrection of Jesus Christ. The faithful believe that Christ rose from the dead on the third day of his death and ascended to heaven, body and soul. Roman Catholics believe that humanity's salvation was earned through the ultimate sacrifice of Christ, and that through the Resurrection and the Ascension, He opened the gates for humanity to enter heaven.
Perhaps the feature that separates Roman Catholicism from other denominations of the Christian faith is their belief that the Pope is an infallible leader, in direct line from Peter, the apostle Jesus called the "rock" on whom the Church would be built. Together with the pope, the Roman Catholic Church is governed by bishops in the College of Cardinals. Bishops or Cardinals are charged with the spiritual guidance of their communities and are spread out across the world. These communities are broken up into parishes, which are led by priests. Catholics believe that the bishops are successors of Jesus' twelve apostles.
Catholicism also calls for the belief in what it calls Divine Mysteries, some tenets of which are not accepted by other Christians. Divine Mysteries include the doctrine of the Holy Trinity, which states that there are three persons in one God - God the Father, God the Son, and God the Holy Spirit or Holy Ghost. It also teaches that the Holy Eucharist is in fact the body of Christ, and not merely a symbol, the veneration of Mary as the Mother of God, the veneration of saints, and practice of the Sacraments or the Sacred Mysteries.
The Sacraments of Catholicism include Baptism, Confirmation, the Holy Eucharist (receiving the communion wafer), Penance (going to confession, Anointing of the Sick or Holy Unction, Holy Orders (entering the priesthood or becoming a nun), and Matrimony. It is commonly believed that the sacraments build on one another. For instance, the most basic sacrament of Catholicism is that of Baptism. Without it, one cannot be considered a Catholic at all and would not be able to proceed to the other sacraments.