Covenant and the Messianic hope
To understand Judaism, you need to understand the covenant. It is an agreement between God and the Jewish people. If the Jews keep their side, God will keep His side. The Jews have to follow the teachings of the Torah. If they do, God will protect them and they will be his chosen people. When you're asked to explain why Jews do something, a standard answer that you can use is that the Torah instructs them to do so. If you want to explain it further, you can say that following the Torah is part of the covenant relationship with God.
The Revision Site's What do Jews Believe? (used in STEP 1) explains this relationship briefly
The covenant is not just about God acting for the Jews in the past (saving them from slavery and giving them the Promised Land). It is also about the future. The Messiah will one day come, bringing peace throughout the world.
Judaism 101 explains this idea of Moshiach: The Messiah
You might get asked the following question (would you be able to answer it?):
(a) Describe and explain what Jews believe about the Messiah [8]
Try to answer the following question [2000 Q5] - although it might not come up again this year, it is central to Judaism and will help your general understanding of the religion.
(a) Describe and explain what Jews believe about the promises G-d has made to them. [8]
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