The dominant theme of the Sermon on the Mount is the righteousness that is the Kingdom of God. That righteousness is the food that His children feed on and the water that sustains and refreshes them.
So what IS that Kingdom righteousness?
It is being poor in spirit and broken over your sinfulness. It is submitting to God's control over your life and being filled with His presence. It is extending mercy from a pure heart and being a peace-maker rather than a trouble-maker. It is being willing to face persecution rather than compromise righteousness.
A truly righteous life will shine light a beacon in a dark world and will make others hungry and thirsty for God.
Righteousness is a result of living in a right relationship with God through Christ. As a relationship it is dynamic not static and must be kept up to date on a moment by moment, day by day basis.
Jesus made it clear He was raising the bar on righteousness when He stated in Matthew 5:20 - "For I tell you that unless your righteousness exceeds that of the scribes and Pharisees, there is no way you will enter the Kingdom of God."
What was the righteousness of the Pharisees? Their righteousness largely consisted of pride, pretense and performance based behavior. But Jesus said if you harbor anger or lust in your heart you are guilty of murder and adultery. Righteousness demands taking your marriage vows seriously. If you want to be righteous keep your word so no one will doubt what you say. God's righteousness loves enemies and responds to them with grace and kindness.
The righteousness that God requires the right priorities. In Matthew 6 demands that we value His righteousness above material concerns. We are told to trust our Heavenly Father to care for us and provide our needs as He feeds the birds. Righteousness trusts in God and isn't overcome by worry.
In chapter 7 Jesus defines righteousness as a personal relationship rather than religious practices and it is expressed in a life built on obedience.
The Kingdom of God is a kingdom of righteousness and that is the clear message of the Sermon on the Mount. To punctuate the point, Jesus draws the sermon to a conclusion with this sober warning:
"Not everyone who says to me, 'Lord, Lord,' will enter the kingdom of heaven, but only he who does the will of my Father who is in heaven. Many will say to me on that day, 'Lord, Lord, did we not prophesy in your name, and in your name drive out demons and perform many miracles?' Then I will tell them plainly, 'I never knew you. Away from me, you evildoers!'
When it comes to hungering and thirsting for righteousness, you'd better get it right - a right relationship with Christ!