William Miller was a Baptist preacher who, through intensive study of the Bible, concluded that Jesus Christ would return to earth between 1843 and 1844. He began preaching this and gained many followers known as Millerites. When Christ did not return on the predicted dates, it caused the Great Disappointment and the Millerite movement dissolved. Some Millerites went on to form the Seventh Day Adventist Church, believing in the imminent second coming of Christ and observance of the Sabbath on Saturday. Ellen White emerged as an influential leader through her prophetic visions which helped shape Seventh Day Adventist beliefs and practices around health, education, and missions.