"Christianity did not come from Judaism rather, Judaism is a perversion of Christianity." — St. Ignatius of Antioch, 1st century AD
Modern Judaism is a perversion of the Old Testament religion which would more accurately be called Hebraism. The beginnings of Judaism take place with the Pharisees, as is reported in the Universal Jewish Encyclopedia:
“The Jewish religion as it is today traces its descent, without a break, through all the centuries, from the Pharisees. Their leading ideas and methods found expression in a literature of enormous extent, of which a very great deal is still in existence. The Talmud is the largest and most important single member of that literature.” - Vol. VIII, p. 474 (1942).
The faith of the Hebrew Bible, which "officially" began with Abraham can be referred to either as Hebraism or Mosaism (after Moses) and has since been fulfilled by its only authentic and legitimate continuation, Christianity. Judaism is the continuation of Pharisaism and is neither identical to the teachings of Moses, nor is it based on the teachings of Moses. Since Judaism is based on the Talmud, Judaism is, in fact, heresy against the teachings of Moses. In far more instances than not, the Talmud contradicts the teachings of Moses, thereby violating Deuteronomy 4:2, in which Moses himself condemns any attempt to change the written doctrine of the Holy Bible.
Judaism (in the more modern sense) began around 70 AD with the destruction of Jerusalem and the founding of an academy at Jabneh by Yochanan ben Zakai, the next transitional period came with Judah HaNasi and the codification of the law around 200 AD, followed by the two Talmuds, one composed in Babylon and the other in Jerusalem (c. 400-500 AD).
Then came the mass conversion in the kingdom of the Khazars, the Messianic expectations with the pseudo-Messiah Sabbatai Zevi, the new reform movements, such as with the Baal Shem Tov and his Hasidic disciples.
“Strictly speaking, it is incorrect to call an ancient Israelite a ‘Jew’ or to call a contemporary Jew an ‘Israelite’ or a ‘Hebrew.’” (The Jewish Almanac, Compiled and Edited by Richard Siegel and Carl Rheins. New York: Bantam Books, 1980) p. 3.)
St. Ignatius of Antioch, also called Ignatius Theophoros (Greek: “God Bearer”), (died c. 110, Rome; Western feast day October 17; Eastern feast day December 20), bishop of Antioch, Syria (now in Turkey), known mainly from seven highly regarded letters that he wrote during a trip to Rome, as a prisoner condemned to be executed for his beliefs. He was apparently eager to counteract the teachings of two groups—the Judaizers, who did not accept the authority of the New Testament, and the docetists, who held that Christ’s sufferings and death were apparent but not real. The letters have often been cited as a source of knowledge of the Christian church at the beginning of the 2nd century.