The idea of “who is a Jew?” is a complicated one. A person is considered to be Jewish if she or she is born to a woman who is Jewish. The Reform movement also believes that a person with a Jewish father is Jewish. A person can convert to Judaism. The State of Israel only accepts conversions into the Orthodox movement though. Unless a person converts into the Orthodox movement, the person will not be considered Jewish by the State of Israel. This is important for individuals who move to Israel under the Law of Return (Weiner, 2015).
There are most certainly Jewish people who do not practice the Jewish faith. Under the Reform branch, this disqualifies a person from being Jewish. Under the Orthodox branch, as long as the mother is Jewish, nothing can disqualify a person from being Jewish. Regardelss of what faith is practiced, if a person has a matrilineal descent, he or she is Jewish (Weiner, 2015).
Whether or not a person believes in a Messiah may or may not impact if the person is Jewish. If the person is from a stricter branch of the faith, it would not. This seems rather ironic. If the person is from a more liberal or reform movement, it would. The Orthodox Jews believe that the concept of a Messiah is a basic Jewish tenet. The word does not mean “savoir” as many mistakenly believe.
Yes, the Jews who believed or continue to believe in these movements are Jewish. This is particularly true in the modern sense with regards to Chasidic Jews. They are merely an Ultra-Orthodox branch of the Jewish faith. Obviously though, another branch may or may not agree with their beliefs and practices.