People are judged by what they do.
The sources are Matthew, xii, 33 and Luke, vi, 44. Here is the second of these as given in the New English Bible:
There is no such thing as a good tree producing worthless fruit, nor yet a worthless tree producing good fruit. For each tree is known by its own fruit; you do not gather figs from thistles, and you do not pick grapes from brambles. A good man produces good from the store of good within himself; and an evil man from evil within produces evil.