The source for quoted passages in the following is: Scrolls from the Dead Sea (Library of Congress Exhibition).
New Testament Jews were mostly Pharisees. They believed a messiah was coming.
"The Pharisees, unlike the Sadducees, maintained the validity of the oral as well as the written law. They were flexible in their interpretations and willing to adapt the law to changing circumstances. They believed in an afterlife and in the resurrection of the dead. By the first century C.E., the Pharisees came to represent the beliefs and practices of the majority of Palestinian Jewry."
The Sadducees frequently opposed the Pharisees. Sources on the period tend to favor the Pharisees and paint the Sadducees in an unfavorable light.
"The Sadducees were priestly and aristocratic families who interpreted the law more literally than the Pharisees. They dominated the Temple worship and its rites, including the sacrificial cult. The Sadducees only recognized precepts derived directly from the Torah as binding. They, therefore, denied the concept of the immortality of the soul, the resurrection of the body, and the existence of angels. The Sadducees were unpopular with the common people."
The Essenes were unhappy with the conflict between Sadducees and Pharisees and formed in response to it. They moved from Jerusalem to the desert where they adopted strict, ascetic practices.
"The Essenes were a separatist group, some of whom formed an ascetic monastic community and retreated to the wilderness of Judea. They shared material possessions and occupied themselves with disciplined study, worship, and work. They practiced ritual immersion and ate their meals communally. One branch did not marry."