👉 Catholicism is a religious faith that originated in Italy and spread throughout Europe, Latin America, and North Africa. It is one of the two largest Christian denominations in the world (the other being Protestantism). The term "catholic" refers to the belief that Jesus Christ is the Son of God and the ruler of the universe, as described in the New Testament of the Bible. Catholics believe in a single God who has three persons: Father, Son, and Holy Spirit.