Know the people because of what they do.
A good tree will produce good fruit, and yet does a bad tree produce good fruit of value?- Good things often not come from people who are bad, just as grapes do not come from a thorn bush.
In the same way, every good tree can produce good fruit.
Adapted from the Christian bible Matthew 7:16-20
Pic courtesy of Matt from-http://publicdomainarchive.com