"But, Mommy, that's no fair! I MISSED him."
"Your poor aim, my dear son, does not make you innocent."
Perhaps that's precisely what God is saying to His children. He is never fooled by our poor aim, or by our carefully crafted cover-ups. He discerns the thoughts and intentions of our hearts, and no matter how much we control our behavior on the outside, He knows every attitude and desire that we harbor deep within.
When we surrender our lives to the Lord, and ask Him to change us, we tend to think of the outward changes: We'll stop drinking, smoking, gossiping. We'll be nicer to our family and give to the poor. God, however, looks deeper. He wants to change our hearts. He wants all those good actions that we plan on doing to come from pure motives. He desires "truth in the inward parts." (Psalm 51:6)
As we move along in our Christian walk, it's easy to became a bit self-satisfied. After all, the world is full of some pretty shady characters. We have plenty of opportunities to compare ourselves to the more sinful. "God, I thank You that I am not like other men," we say (though perhaps not out loud.) (Luke 18:11) But, the Lord is not content with our outwardly righteous behavior. He sees past all of that, and reaches into our hearts. He looks at our thoughts and our attitudes. He loves us too much to settle for a good-looking exterior. Through time and circumstances, the Lord continually pushes us to examine our intentions, to truly transform our souls.
If we decide we want to be mature Christians (and consider that decision carefully- the road is harder than it looks), then we have to surrender not just the things that we do, but the things that we think to God's refining fire. It's not enough to not hit our brother, we have to forgive him and let go of the desire to hit him. We're human, and our thoughts and attitudes are unruly, but God is faithful. He will complete the work that He starts in us if we let Him.
Our Father is, of course, concerned with our actions. And we should be too. Thinking something isn't the same as doing something. (I'm sure the targeted brother was relieved that he missed.) Contemplating adultery and committing adultery are two very separate things with very different effects. But Jesus said that He wasn't willing to only say, "You shall not commit adultery." His calling was higher: Don't lust. Stop the action at the heart. Why? Because our heart thoughts are what lead to our actions. It might be possible to cherish desires for years without acting, but eventually, something will have to give. Our hearts determine what kind of people we really are. And God focuses on our hearts because He knows that only He has the power to change them.
"I will give you a new heart and put a new spirit within you...
I will put My Spirit within you and cause you to walk in my statutes...
You shall be My people,
and I will be your God."