God, as a loving father, gave Adam and Eve only one rule to keep. Just one. By keeping it, they could show their goodness.
Otherwise, they would simply be as animals, living by instinct, or as robots, under His total control. No rule = no way to show obedience to God, which is the essence of Goodness.
So, He made it easy for them.
But alas, where there is free-will, a higher being and a Rule, there is the possibility for rebellion.