Of course non Christians behave in a non Christian manner. That’s simply the fruit of the worldview that they hold. I can’t shout at my cherry tree for not producing apples or curse my apple tree for not producing cherries. They are simply different trees that produce different kinds of fruit. That’s why Jesus could be friends with unbelieving prostitutes, drunkards and swindlers who simply lived in the light of their unbelieving worldview, but clashed with the Pharisees who pretended to be something that they were not.
From the book "Straight to the Heart of 1 & 2 Corinthians: 60 Bite-sized Insights (The Straight to the Heart Series)"