Proverbs 18:5 (ESV)

5 It is not good to be partial to the wicked or to deprive the righteous of justice.

Being biased to the wicked necessarily entails being unjust to the righteous: when sin is valued, righteousness becomes devalued. One who nurtures and acts in accordance with his natural liking for wickedness will have an equal aversion to righteousness. A person like this is not good and does no good. Such a person will answer to the good Lord for such evil.