Abel Morgan Sarjent (September 6, 1764-August 10, 1839) was a former Universalist minister who founded a religious sect called the Halcyon Church in what is now Mason County on July 11, 1802. He was probably born in Maryland.

Halcyon tenets proclaimed that the end of time was near, when the wicked would be destroyed while the pure-hearted would be saved. Sarjent decried fleshly appetites and advocated a temperate diet of vegetables and milk. He became one of Western Virginia's first prominent men to openly denounce slavery and aid the escape of runaway slaves. Women, another oppressed group that attracted his support, were allowed to become ministers in his church.

Sarjent's following grew rapidly as he traveled through Western Virginia, western Pennsylvania, Ohio, and Kentucky preaching, debating other ministers, and publishing a religious periodical and numerous tracts. By 1807, Halcyons, numbering in the thousands, extended from Louisville to Pittsburgh.

Dissension soon weakened the new religion. A few younger Halcyons broke from Sarjent's control. Accounts of extreme fasting and bizarre behavior, linked with stories labeling Sarjent a charlatan, damaged his credibility. So did the jealousy of other ministers, mainly Methodists and Baptists alarmed by his sudden fame and success. Peaking about 1807, the Halcyon Church slid into decline. Less than a decade later it was extinct. Many Halcyons became Universalists. The Mormons later incorporated some Halcyon principles into their faith.

Abel Sarjent died in Indiana, nearly forgotten by the people of the Ohio Valley.