John Chrysostom
Catena Aurea · Lukasevangelium 3
Then said he to the multitude that came forth to be baptized of him, O generation of vipers, who hath warned you to flee from the wrath to come? Bring forth therefore fruits worthy of repentance, and begin not to say within yourselves, We have Abraham to our father: for I say unto you, That God is able of these stones to raise up children unto Abraham. And now also the axe is laid unto the root of the trees: every tree therefore which bringeth not forth good fruit is hewn down, and cast into the fire,
(ubi sup.) Not meaning thereby that they had not descended in their natural course from Abraham, but that it avails them nothing to have Abraham for their father, unless they observed the relationship in respect of virtue. For Scripture is accustomed to entitle laws of relationship, such as do not exist by nature, but are derived from virtue or vice. To whichsoever of these two a man conforms himself, he is called its son or brother.