Jesus Christ is the most important person who ever set foot on planet earth because he was and is God Almighty in human flesh. He came from heaven into this world of suffering and death to save all mankind from sin and the sad consequences of sin – ignorance of God, suffering and death. He is the only one who could possibly reconcile man with God, since as God all his actions have infinite merit.     It is a sad fact that many Catholics do not know the fundamentals of their religion. They do now know that Jesus of Nazareth is God in human flesh; they do not know that the resurrected Jesus is truly present – body, blood, soul, and divinity – under the appearances of bread and wine after the consecration by the priest as Mass. They do not know really what the Sacraments are.     Because of the gross ignorance among many Catholics about Jesus, this short handbook on Christology was written as a way of instructing Catholics about Jesus as both God and man. The word “Christology” means the science or study of Christ. This little book offers a summary of Catholic doctrine on such points as the divinity of Christ, the Hypostatic Union, the resurrection and the infinite knowledge and power of Jesus as our Savior.     The doctrine contained in this handbook is based on the Catechism of the Catholic Church and the teaching of St. Thomas Aquinas, the Angelic Doctor and prince of theologians. The book can profitably be used as a companion to Pope Benedict XVI’s Jesus of Nazareth because it explains the Church’s official doctrine about Jesus that is alluded to in the Pope’s book which is a scriptural presentation.