21 “You have heard that it was said to the people long ago, ‘You shall not murder, and anyone who murders will be subject to judgment.’ 22 But I tell you that anyone who is angry with a brother or sister will be subject to judgment. Again, anyone who says to a brother or sister, ‘Raca,’ is answerable to the court. And anyone who says, ‘You fool!’ will be in danger of the fire of hell.
Have you ever been in a situation where you thought you had done all of what was required of you, only to find out there was more to do? You wanted to say, "really" more to do! Jesus starts in a series of teachings that will leave the religious folks, like the Pharisees, saying, "Really we thought we had done all that the Law requires". Jesus begins a series of teachings that begin with "You have heard that it was said..." Jesus is taking, in this instance, the minimum requirement of the Law, and going far beyond to the spirit of law.
For instance someone could say, "Well i have never murdered anyone, so i got this one down. Next!" But Jesus says, whenever we are angry at someone, or call them degrading names, we are guilty of murder. Of course not in the same way, but in the same spirit. For when we express destructive anger toward someone, are we not killing the relationship and doing damage to their soul. And when we call someone names, are we not killing their reputation, or demeaning their self worth.
I think Jesus is addressing a situation where we are willing to address the letter of the Law, but not what it really requires. Whereas the outward law looks only at outward behavior, Jesus is getting at the heart. He is getting at a heart where anger is often times the knee jerk response to family and friends. Or, when we get ticked off at someone, calling them names is the usual order of the day. In either case, it reveals something is going on inside us that is not right! Our heart condition needs some major work. Our words or actions reveal what is going on in the heart.
In the end, I think we are all guilty just doing the minimum to avoid the big consequences. But Jesus wants us to go deeper into our hearts, where relationships are built and destroyed. He called the Pharisees, "White washed tombs!" Why? Because they looked all white and shiny on the outside, but the inside they were dying corpses.
As we go through Jesus' "You have heard it said..." analogies we have a chance to go beyond the letter of the Law to its true meaning. This is the true lithmus test of our spiritual health and walk with Jesus.