Jesus knows something and he wants religious people to understand it. Who we are is a result of what we think. If we think about committing adultery, we have done it. What makes us “UN-virtuous” is what we think, not what we do.
This is a huge thing to grasp. Jesus knows, for religious people, it is way to easy to “get around” moral rules and still violate the principle God has in mind every day. We need to change how we think (repent) about God’s word.
“Don’t think you’ve preserved your virtue simply by staying out of bed with someone who is not your wife.” ~~Jesus (Matthew 5 The Message)