God spoke, and these were his words: you shall have no other gods to set against me. you shall not make a carved image for yourself nor the likeness of anything in the heavens above you shall not bow down to them you shall not make wrong use of the name of the lord your god remember to keep the sabbath day holy. --the new english bible

2. what is the fundamental belief of judaism and christianity referred to in the above statement?

The fundamental belief of Judaism and Christianity referred to in the above statement is monotheism.

Explanation:

Both Judaism and Christianity are the branches of a single tree as the ancestry of both the religions can be traced back to a single entity.A monotheistic religion is the one in which the followers of the religion worship only one God. It preaches that the God is only singular and is present  in a single original form.The God may choose to reach his subjects through various means and through multiple people called messengers at the same time, but God himself does not exist in multiple forms.