Theft is forbidden. The world is not ours to do with as we please
The prohibition of theft is contained within the permission which G-d granted to Adam and Eve in Genesis 2:16 to eat from the trees of the garden. This implies that if the permission had not been granted, they would have been forbidden to do so, because the property did not belong to them. This applied specifically to the fruit of the Tree of "Knowledge of Good and Evil" which was forbidden for them to take, under penalty of death (Genesis 2:16-17).
