God has created the universe in a certain manner – I call this the natural law of the universe. His natural law corresponds to the Torah which is an explanation of how a nation should conduct itself according to His natural law. The Torah also includes special commands that relate to Israel getting a concrete view of how God made things. For instance the Temple was to be created in a very specific manner which relates to the Temple in heaven (which will reside on earth in the next age – Rev. 21). It is a viewable, touchable (concrete) model of the Heavenly Temple.
The Torah is built on the principle of loving another as you love yourself. This is the way God originally created things. Whatever deviates from this rule is unnatural and evil because it is against the way God created the universe and intends that it should be maintained. Imagine a world in which everyone loved each other as they loved themselves! This was the world of Adam and Eve!
We get an insight into this from Paul where he states that love is the fulfilling of the law because it does no harm to your neighbor. The word “Ra” in Hebrew which is translated as evil actually means harm. To harm others intentionally is against the natural law (which has been corrupted) of the universe.