A person serves God by studying the Torah and living by its teachings.
Jewish history begins c. 3150 BCE in the Middle East. The birth of the Jewish people and the start of Judaism is told in the first 5 books of the Bible. God chose Abraham to be the father of a people who would be special to God, and who would be an example of good behaviour and holiness to the rest of the world.
God guided the Jewish people through many troubles, and at the time of Moses he gave them a set of rules by which they should live, including the Ten Commandments.
This was the beginning of Judaism as a structured religion The Jews, under God’s guidance became a powerful people with kings such as Saul, David, and Solomon, who built the first great temple.
Orthodox Judaism: Orthodox Judaism is the most traditional expression of modern Judaism. Orthodox Jews believe the entire Torah - including "Written," the the Pentateuch, and "Oral," the Talmud) was given to Moses by God at Sinai and remains authoritative for modern life in its entirety. According to a 1990 nationwide survey, 7 percent of American Jews are Orthodox. American and Canadian Orthodox Jews are organized under the Orthodox Union, which serves 1,000 synagogues in North America.
Reform Judaism: Reform Judaism is the most liberal expression of Judaism. In America, Reform Judaism is organized under the Union for Reform Judaism (known as the Union of American Hebrew Congregations until 2003), whose mission is "to create and sustain vibrant Jewish congregations wherever Reform Jews live." About 1.5 million Jews in 900 synagogues are members of the Union for Reform Judaism. According to 1990 survey, 42 percent of American Jews regard themselves as Reform.
Conservative Judaism: Conservative Judaism may be said to be a moderate position between Orthodox and Reform Judaism. It seeks to conserve the traditional elements of Judaism, while allowing for modernization to a less radical extent than Reform Judaism. The teachings of Zacharias Frankel (1801-75) form the foundation of Conservative Judaism.
Hasidic Judaism: Hasidic (or Chasidic) Judaism arose in 12th-century Germany as a mystical movement emphasizing asceticism and experience born out of love and humility before God. The austere religious life of these early Hasids ("pious ones") is documented in the Sefer Hasidim ("Book of the Pious"). The modern Hasidic movement was founded in Poland in the 18th century by Israel ben Eliezer, more commonly known as the Baal Shem Tov ("Master of the Good Name") or "the Besht" (an acronym for Baal Shem Tov).
Kabbalah: The mystical form of Judaism is Kabbalah. Broadly speaking, Kabbalah refers to Jewish mysticism dating back to the time of the second Temple. For many years a carefully guarded oral tradition, it became systematized and dispersed in the Middle Ages. The kabbalistic viewpoint was expressed most importantly in the Yalkut Re'uveni by Reuben Hoeshke in 1660, but also made its way into prayer books, popular customs and ethics. The focus of the Kabbalah is the simultaneous transcendence and immanence of God, with the latter described in terms of the sefirot, or attributes of God.