I believe they had an acquaintance with the concept of good and evil (eat; don't eat), and that after eating the fruit of the tree they had a more intimate knowledge of it.
Acquaintance with the concept of good and evil? Hmmm...
<<<eat;don’t eat>>>
Such is amoral, is it not?
Besides, if one considers the commandment to not eat of the fruit of the tree of knowledge of good and evil, such belief could not be implied nor inferred in it. However, what it implies is that they do not have such knowledge, and that if and when they eat of it, they would have such knowledge.
Tong
R1361