What were the four major groups of the Jewish society during the time of the Roman Empire?

Answer 1

1) The Jewish group that concentrated on the study, teaching and application of the Torah in every century was and is the Torah-sages and their many disciples, from Abraham down to today.
The word "Pharisees," which is based on a Greek misspelling used by Josephus, actually refers to the Sages of the Talmud. (The Hebrew word "p'rushim," to which he referred, means people of temperance; the opposite of epicurean.)The Torah-sages such as Rabbi Yochanan ben Zakkai, Rabbi Yonatan ben Uziel, Chanina ben Dosa, Bava ben Buta, Shimon ben Hillel, Rabbi Eliezer, Rabbi Yehoshua, Rabbi Akiva, and hundreds of others, were active at that time and their yeshivot (Torah-academies) were flourishing. Their tens of thousands of disciples and hundreds of thousands of sympathizers were active in the Jewish world in that generation; they were the leaders and the forefront of Judaism.

Josephus talks of three groups among the Jews in late Second-Temple times: Pharisees, Sadducees, and Essenes. This may convey the mistaken impression that the Pharisees were just one "sect" among others, when in fact Josephus himself admits that the Pharisees (Torah-sages) with their disciples and followers constituted the large majority of the Jewish people. As he himself writes (Antiquities book 18), "the cities give great attestations to them."
Although the Christian Testament portrays them poorly, in fact the Pharisees were very egalitarian. They taught that all men were created in God's image and that all had the same rights, and the same right to an education, etc. They were devoted to the practicing of kindness, charity, the fulfillment of mitzvot, the study and teaching of Torah and the education of all people, regardless of status in society. They detested hypocrisy and actively sought it out and criticized it whenever they encountered it.

The Pharisees were the only movement to survive the destruction of the Second Temple and were the ancestors of modern Judaism.
Our traditional Jewish beliefs today, including the afterlife and the resurrection, are traditions continuing from the Prophets and the Sages of the Talmud ("Pharisees").

2) The Sadducees. These were men of politics and secular life, similar to the Hellenising Jews. They had abandoned various parts of Judaism; and they claimed no earlier source or tradition for their attitudes. They harassed the Torah-sages; and, like the tiny breakaway group called the Essenes, dwindled away after the time of the Second Destruction, like the earlier Jewish idolaters after the First Destruction.

Note that there is a common misconception that the Sadducees, like the much later (and now largely defunct) Karaites, made a deliberate decision to reject the Oral Law and reinterpret the Scriptures.
However, a careful perusal of the Talmud reveals that the Sadducees were actually opportunists who had nothing much at all to do with religion in any fashion. They were lax in Judaism and had little interest in Torah-matters.

At that time the Jewish courts still had the ability to enforce the Torah laws, and almost all Jews were Torah-observant; so, in order to avoid total rejection by the surrounding community, the Sadducees outwardly maintained a facade of keeping the major Torah precepts (such as the Sabbath), while simply ignoring the Oral Torah and customs.
They went lost not long after.
The group that did (on rare occasions) debate against the Torah-Sages concerning subjects of religious observance, were a tiny sect called the Baitusim (Boethusians), who quickly died out.

3) The Essenes were a small sect in Judea who eventually disappeared from the Jewish community. They styled themselves "observant; pious ones." The normative, majority Jewish community viewed them as breakaways from the common stream of Jewish tradition, because of their non-traditional beliefs and practices.

Their beliefs included an excessive amount of dabbling with the names of angels, messianic fervor, gnosticism and eschatological speculation; and their practices were more like Christian monasticism than the generally accepted Jewish way of living.

The practices of the Essenes included vegetarianism, dwelling in isolated groups, communal ownership, monastic asceticism and avoidance of money, commerce and private property; and (among some of them) celibacy. Also, they had some forms of non-traditional observances (such as round phylacteries [tefillin]). Some researchers identify the Essenes as a form of early Christianity, taking also into account the fact that early Christianity was far from uniform and was, for a time, thought of by some as a kind of modified Judaism.

4) The Samaritans. After the Assyrians exiled the Israelite Ten Tribes (about 2600 years ago), the Assyrian king brought non-Jews from Cutha, Babylonia and Syria (Hamat), and settled them in the depopulated area where the Ten Tribes had lived (Samaria). They were taught Judaism by one of the Jewish kohens (2 Kings 17:27), and they were taught the Torah, which they wrote in the Old Hebrew script.

While both Jews and Samaritans believed in One God, and both accepted the Torah, there were also some differences. Jerusalem was and is the holiest site for Jews, while the Samaritans took Mount Gerizim as their religious center. Later in history, the Samaritans aligned with the Greeks and accepted foreign gods (Talmud, Hullin 6a).

The Talmud relates how the Samaritans adopted some of the mitzvot (Torah-commands) but not others (Talmud, Berakhot 47b), how they denounced the Jews to Alexander in an unsuccessful bid to get him to destroy the newly-built Second Temple (Talmud, Yoma 69a), and how they interfered with the declaring of Rosh Hodesh (the New Moon) (Talmud, Rosh Hashanah 22b). Our traditions relate how the Samaritans would sometimes waylay the Jews who tried to journey to the Holy Temple.

Today the Samaritans are a small group of about 800, who practice an ancient form of Jewish worship, with animal sacrifices. They don't accept the Talmud, nor holidays such as Hanukkah.

5) The Zealots. These were a group of dangerous hotheads who acted against the advice of the Rabbis and fomented war against the Romans, leaving the Romans no choice but to crush the people and destroy the city of Jerusalem (Talmud, Gittin 56).

Answer 2

1) The Jewish group that concentrated on the study, teaching and application of the Torah in every century was and is the Torah-sages and their many disciples, from Abraham down to today.
The word "Pharisees," which is based on a Greek misspelling used by Josephus, actually refers to the Sages of the Talmud. (The Hebrew word "p'rushim," to which he referred, means people of temperance; the opposite of epicurean.)The Torah-sages such as Rabbi Yochanan ben Zakkai, Rabbi Yonatan ben Uziel, Chanina ben Dosa, Bava ben Buta, Shimon ben Hillel, Rabbi Eliezer, Rabbi Yehoshua, Rabbi Akiva, and hundreds of others, were active at that time and their yeshivot (Torah-academies) were flourishing. Their tens of thousands of disciples and hundreds of thousands of sympathizers were active in the Jewish world in that generation; they were the leaders and the forefront of Judaism.

Josephus talks of three groups among the Jews in late Second-Temple times: Pharisees, Sadducees, and Essenes. This may convey the mistaken impression that the Pharisees were just one "sect" among others, when in fact Josephus himself admits that the Pharisees (Torah-sages) with their disciples and followers constituted the large majority of the Jewish people. As he himself writes (Antiquities book 18), "the cities give great attestations to them."
Although the Christian Testament portrays them poorly, in fact the Pharisees were very egalitarian. They taught that all men were created in God's image and that all had the same rights, and the same right to an education, etc. They were devoted to the practicing of kindness, charity, the fulfillment of mitzvot, the study and teaching of Torah and the education of all people, regardless of status in society. They detested hypocrisy and actively sought it out and criticized it whenever they encountered it.

The Pharisees were the only movement to survive the destruction of the Second Temple and were the ancestors of modern Judaism.
Our traditional Jewish beliefs today, including the afterlife and the resurrection, are traditions continuing from the Prophets and the Sages of the Talmud ("Pharisees").

2) The Sadducees. These were men of politics and secular life, continuing in the ways of the Hellenising Jews. They had abandoned various parts of Judaism; and they claimed no earlier source or tradition for their attitudes. They harassed the Torah-sages; and, like the tiny breakaway group called the Essenes, dwindled away after the time of the Second Destruction, like the earlier Jewish idolaters after the First Destruction.

Note that there is a common misconception that the Sadducees, like the much later (and now largely defunct) Karaites, made a deliberate decision to reject the Oral Law and reinterpret the Scriptures.
However, a careful perusal of the Talmud reveals that the Sadducees were actually opportunists who had nothing much at all to do with religion in any fashion. They were lax in Judaism and had little interest in Torah-matters.

At that time the Jewish courts still had the ability to enforce the Torah laws, and almost all Jews were Torah-observant; so, in order to avoid total rejection by the surrounding community, the Sadducees outwardly maintained a facade of keeping the major Torah precepts (such as the Sabbath), while simply ignoring the Oral Torah and customs.
They went lost not long after.
The group that did (on rare occasions) debate against the Torah-Sages concerning subjects of religious observance, were a tiny sect called the Baitusim (Boethusians), who quickly died out.

3) The Essenes were a small sect in Judea who eventually disappeared from the Jewish community. They styled themselves "observant; pious ones." The normative, majority Jewish community viewed them as breakaways from the common stream of Jewish tradition, because of their non-traditional beliefs and practices.

Their beliefs included an excessive amount of dabbling with the names of angels, messianic fervor, gnosticism and eschatological speculation; and their practices were more like Christian monasticism than the generally accepted Jewish way of living.

The practices of the Essenes included vegetarianism, dwelling in isolated groups, communal ownership, monastic asceticism and avoidance of money, commerce and private property; and (among some of them) celibacy. Also, they had some forms of non-traditional observances (such as round phylacteries [tefillin]). Some researchers identify the Essenes as a form of early Christianity, taking also into account the fact that early Christianity was far from uniform and was, for a time, thought of by some as a kind of modified Judaism.

4) The Samaritans. After the Assyrians exiled the Israelite Ten Tribes (about 2600 years ago), the Assyrian king brought non-Jews from Cutha, Babylonia and Syria (Hamat), and settled them in the depopulated area where the Ten Tribes had lived (Samaria). They were taught Judaism by one of the Jewish kohens (2 Kings 17:27), and they were taught the Torah, which they wrote in the Old Hebrew script.

While both Jews and Samaritans believed in One God, and both accepted the Torah, there were also some differences. Jerusalem was and is the holiest site for Jews, while the Samaritans took Mount Gerizim as their religious center. Later in history, the Samaritans aligned with the Greeks and accepted foreign gods (Talmud, Hullin 6a).

The Talmud relates how the Samaritans adopted some of the mitzvot (Torah-commands) but not others (Talmud, Berakhot 47b), how they denounced the Jews to Alexander in an unsuccessful bid to get him to destroy the newly-built Second Temple (Talmud, Yoma 69a), and how they interfered with the declaring of Rosh Hodesh (the New Moon) (Talmud, Rosh Hashanah 22b). Our traditions relate how the Samaritans would sometimes waylay the Jews who tried to journey to the Holy Temple.

Today the Samaritans are a small group of about 800, who practice an ancient form of Jewish worship, with animal sacrifices. They don't accept the Talmud, nor holidays such as Hanukkah.

5) The Zealots. These were a group of dangerous hotheads who acted against the advice of the Rabbis and fomented war against the Romans, leaving the Romans no choice but to crush the people and destroy the city of Jerusalem (Talmud, Gittin 56).

See also:

Jewish history timeline

Answer 3

There were actually five main groups of Jews at the time of Jesus: Pharisees (the forerunners of Modern Jewry), the Sadducees, the Essenes, the Zealots, and the Samaritans. I suggest reading the Expert Answer of Dan Galilee below for in-depth information about these groups.

Answer 4

The four groups, generally speaking, were: the Pharisees, Sadducees, Essenes, and Zealots.