Either make the tree good and its fruit good, or make the tree rotten and its fruit rotten; for the tree is known by its fruit.

and noticing a fig tree by the roadside he went up to it, but found nothing on it except leaves. He said to it, "May no fruit ever come from you after this!" And instantly the fig tree withered up.

every good tree bears sound fruit, but a rotten tree bears bad fruit;

a good tree cannot bear bad fruit, and a rotten tree cannot bear sound fruit.

The axe is lying all ready at the root of the trees; any tree that is not producing good fruit will be cut down and thrown into the fire.