Christianity is a monotheistic religion centered on the life and teachings of Jesus of Nazareth, the Christ (Messiah) or Savior and Son of God (an incarnation of God), as relayed in the New Testament of the Bible. Beginning as a Jewish sect, by the 4th century Christianity had become the dominant religion of the Roman Empire. A consummately virtuous historical figure, some say that Jesus spent his adult life in Northern India and Kashmir, in study of the highest wisdom of the planet at that time. At age 30, Jesus returned to Judea to fulfill perhaps the greatest spiritual mission of anyone in known history by taking the spiritual karma of humanity onto himself, through full sacrifice. Christianity is characterized by the faith that Jesus suffered persecution, died from crucifixion, was buried, and then ascended from the dead principally to open the way to Heaven for those who believe in him and trust him for the remission of their sins (salvation).