The Essenes were members of a small Jewish religious order, originating in the 2d cent. BC. The main sources of information about the Essenes are Pliny the Elder, Philo's Quod omnius probus liber, Josephus' Jewish War and Antiquities of the Jews, and the Dead Sea Scrolls .

The Essenes consisted of adult males and celibacy was encouraged. The Essenes lived as a highly organized community that held possessions in common. Ceremonial purity entailed scrupulous cleanliness, the wearing of only white garments, and the most strict observance of the Sabbath.

The Essenes believed in the immortality of the soul. Their practice, common among many Jewish groups, of purification through ritual immersion may have been a significant influence on the development of the rite of baptism in the early Christian church. They condemned slavery and prohibited trading because it led to covetousness and cheating; they avoided luxury, abhorred untruthfulness and forbade oaths, with the one exception of the oath a new member took after two years of probation. In this oath, the member pledged piety toward God, justice to men, honesty with fellow Essenes, preservation of the sect's secrets, and proper transmission of its teachings.

The Essenes subsisted by pastoral and agricultural activities and handicrafts; they avoided the manufacture of weapons. There is evidence of Persian and Hellenistic influences in the sect's thought. The Essenes' belief in several Messiahs is thought by some to have been a major influence in the development of Christianity.