The three Abrahamic faiths are Judaism, Christianity, and Islam. They are related through several fundamental beliefs and a shared history, beginning with the figure of Abraham. These three religious traditions are called "Abrahamic" because they each trace their beginning to Abraham, who founded the Covenant (relationship of respect and obligation) between his people and God. The Abrahamic Covenant, specifically, was God's promise to protect and shepherd Abraham's descendants, and Judaism, Christianity, and Islam all value this Covenant but may have different opinions about what else happened between God and mankind. For example, Christianity holds that Jesus Christ was prophesied as the Messiah and died for the forgiveness of all sins. In Islam, while Jesus Christ is regarded as a prophet, he is not believed to have been the Messiah.
One of the main things the Abrahamic faiths have in common is that they are monotheistic. That means they believe in just one god, the God, who is creator of all things.
These three religions also share similar cosmologies and eschatologies. Cosmology deals with how the world and the universe were created, and the Abrahamic traditions agree that God created the world, separating the once united heavens and earth, in six days and took a rest on the seventh. Eschatology has to do with the end of a person's life as well as the "end of time," and all three religions hold that if a person acts in accordance with God's will during their time on Earth, there is peace awaiting them after death. They also believe that there will come a time when God will intervene on Earth and make it into a paradise, banishing people who do not act in accordance with God's will, for some amount of time.
In practice, the three Abrahamic faiths have some traditional rules regarding personal conduct. All three religions engage in periods of fasting throughout the year, observe a weekly holy day, and encourage regular, ritualized prayer. Of course, the extent to which individuals hold to these rules varies widely. Judaism, Christianity, and Islam each also have a holy book containing many of the same stories of creation, God's stewardship of mankind, and rules for living.