We often make the mistake of thinking that in the Old Testament you had all these commandments and Jesus came along and made life easier. The gospel today is just one example of how he not only made it more difficult; he made it impossible.
You have heard that it was said to your ancestors, You shall not kill; and whoever kills will be liable to judgment. But I say to you, whoever is angry with his brother will be liable to judgment, and whoever says to his brother, Raqa, will be answerable to the Sanhedrin, and whoever says, ‘You fool,’ will be liable to fiery Gehenna.
How are we supposed to go through life without even getting angry? For a human being that is impossible. But that is why he gave us grace.
Jesus didn't lower the bar. He raised it. Love your enemies. Turn the other cheek. Don't get angry. All of these things and more are impossible for us to do on our own. But with the help of God's grace we can do them all. And how do we get grace? Sacraments.
Jesus gave us the sacraments through which we receive the gift of grace, beginning with Baptism. From there we are called to live constantly in a state of grace. To help us stay in that state we have the Eucharist. "Give us this day our daily bread." That bread of life is available to us daily in churches all over the world to constantly nourish us and renew the grace within us.
And for the time when we step thoroughly out of the state of grace, we have the sacrament of Penance or Reconciliation. I say step out rather than fall out, because you can accidentally fall, but you can't accidentally sin. Moral sin requires volition. You choose to step out of God's grace.
Eucharist and Penance were established by Christ to constantly make possible the impossible.
I tell you, unless your righteousness surpasses that of the scribes and Pharisees, you will not enter into the Kingdom of heaven.
The scribes and Pharisees were not bad people they tried to know and follow the law. And yet we are told we must outdo them all if we want to get into heaven. And how do we do that? With God's grace constantly helping us: to know what is right, to want what is right, and to do what is right.