A sound tree cannot produce bad fruit, nor can a worthless tree bear good fruit.
So, too, every sound tree bears good fruit, while a worthless tree bears bad fruit.
Every tree that fails to bear good fruit is cut down and thrown into the fire.
There is no such thing as a good tree bearing worthless fruit, or, on the other hand, a worthless tree bearing good fruit.
For these cravings of our earthly nature conflict with the Spirit, and the Spirit with our earthly nature--they are two contrary principles--so that you cannot do what you wish.