Judaism
There are some movements that combine elements of Judaism with those of other religions. The most well-known of these is Messianic Judaism, a religious movement, which arose in the 1960s, that incorporates elements of Judaism with the tenets of Christianity. The movement generally states that Jesus is the Jewish Messiah, that he is one of the Three Divine Persons, and that salvation is only achieved through acceptance of Jesus as one's savior. Some members of the movement argue that Messianic Judaism is a sect of Judaism. Jewish organizations of every denomination reject this, stating that Messianic Judaism is a Christian sect, because it teaches creeds which are identical to those of Pauline Christianity.
Orthodox Judaism
Orthodox Judaism is not a centralized denomination. Relations between its different subgroups are sometimes strained, and the exact limits of Orthodoxy are subject to intense debate. Very roughly, it may be divided between Ultra-Orthodox or "Haredi", which is more conservative and reclusive, and Modern Orthodox Judaism which is relatively open to outer society. Each of those is itself formed of independent streams. They are almost uniformly exclusionist, regarding Orthodoxy as the only authentic form of Judaism and rejecting all competing non-Orthodox philosophies as illegitimate. While adhering to traditional beliefs, the movement is a modern phenomenon. It arose as a result of the breakdown of the autonomous Jewish community since the 18th century, and was much shaped by a conscious struggle against the pressures of secularization and rival alternatives. The strictly observant and theologically aware Orthodox are a definite minority among all Jews, but there are also numerous semi- and non-practicing persons who are officially affiliated or personally identifying with the movement. In total, Orthodox Judaism is the largest Jewish religious group, estimated to have over 2 million practicing adherents and at least an equal number of nominal members or self-identifying supporters.