Paula Fredriksen, in From Jesus to Christ, has suggested that Jesus' impact on his followers was so great that they could not accept this failure. According to the New Testament, some Christians believed that they encountered Jesus after his crucifixion; they argued that he had been resurrected (the belief in the resurrection of the dead in the messianic age was a core Pharisaic doctrine), and would soon return to usher in the Kingdom of God and fulfill the rest of Messianic prophecy such as the Resurrection of the dead and the Last Judgment. Others adapted Gnosticism as a way to maintain the vitality and validity of Jesus' teachings (see Elaine Pagels, The Gnostic Gospels).