They that forsake the law praise the wicked: but such as keep the law contend with them.
The few commentaries I have read on this verse speak in reference to the laws of the land. While I agree that that might fit this proverb, I also believe it speaks of God's law. Those of us who have a relationship with Christ should not sit quietly by as others forsake God's law. By doing so, we would be condoning the behavior. This verse says we should "contend" which means to stand against and fight. We can not be pacifists. We must stand for God's law.
Romans 12:9 says, "Abhor that which is evil". You can not sit quietly by if you truly abhor the evil being committed.