Ellen G. White in the context of "Smithsonian (magazine)"

The Seventh-day Adventist Church (SDA) is an Adventist Protestant Christian denomination which is distinguished by its observance of Saturday, the seventh day of the week in the Christian (Gregorian) and the Hebrew calendar, as the Sabbath; its emphasis on the imminent Second Coming (advent) of Jesus Christ; and its annihilationist soteriology. The denomination grew out of the Millerite movement in the United States during the mid-19th century, and it was formally established in 1863. Among its co-founders was Ellen G. White, whose extensive writings are still held in high regard by the church.

Much of the theology of the Seventh-day Adventist Church corresponds to common evangelical Christian teachings, such as the Trinity and the infallibility of Scripture. Distinctive eschatological teachings include the unconscious state of the dead and the doctrine of an investigative judgment. The church emphasizes diet and health, including adhering to Jewish dietary law, advocating vegetarianism, and its holistic view of human nature—i.e., that the body, soul, and spirit form one inseparable entity. The church holds the belief that "God created the universe, and in a recent six-day creation made the heavens and the earth, the sea, and all that is in them, and rested on the seventh day." Marriage is defined as a lifelong union between a man and a woman. The second coming of Christ and resurrection of the dead are among official beliefs.

Adventism is a branch of Protestant Christianity that believes in the imminent Second Coming (or the "Second Advent") of Jesus Christ. It originated in the 1830s in the United States during the Second Great Awakening when Baptist preacher William Miller first publicly shared his belief that the Second Coming would occur at some point between 1843 and 1844. His followers became known as Millerites. After Miller's prophecies failed, the Millerite movement split up and was continued by a number of groups that held different doctrines from one another, being Ellen G. White the best known leader and writer. These groups, stemming from a common Millerite ancestor, collectively became known as the Adventist movement.

Although the Adventist churches hold much in common with mainline Christianity, their theologies differ on whether the intermediate state of the dead is unconscious sleep or consciousness, whether the ultimate punishment of the wicked is annihilation or eternal torment, the nature of immortality, whether the wicked are resurrected after the millennium, and whether the sanctuary of Daniel 8 refers to the one in heaven or one on earth. Seventh-day Adventists and some smaller Adventist groups observe the seventh day Sabbath. The General Conference of Seventh-day Adventists has compiled that church's core beliefs in the 28 Fundamental Beliefs (1980 and 2005).

The investigative judgment, or pre-Advent Judgment (or, more precisely, the pre-Second Advent Judgment), is a unique Seventh-day Adventist doctrine which asserts that the divine judgment of professed Christians has been in progress since 1844. It is intimately related to the history of the Seventh-day Adventist Church and was described by one of the church's pioneers Ellen G. White as one of the pillars of Adventist belief. It is a major component of the broader Adventist understanding of the "heavenly sanctuary", and the two are sometimes spoken of interchangeably.