They would be incorrect. Christ never abolished the law, instead he finished the law. We are held to an even higher standard than obeying the written law by not committing the act, we must not even allow the notion to enter our hearts. Christ told us that even were we to lust after a woman, then we have committed adultery in our hearts.
"For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished." ... Matthew 5:18
So, even lusting for a ham and cheese sandwich is a sin?
And apparently, if you are angry with another person, you are guilty of murder.