The kingdom of heaven was not at all what the Jews of Jesus’ day expected. Jesus describes the kingdom from its attitudes (Matt 5:3–10), and declares that His coming had not broken the Law or the Prophets but fulfilled them (Matt 5:17). The attitude of the kingdom toward God’s law was going to be one of understanding and obedience (Matt 5:19–20). The Pharisees and teachers of the law had considered themselves righteous by their observance of God’s law (Luke 18:9), but the righteousness of the kingdom was going to be greater than that of the Jewish leaders (Matt 5:20).
“You have heard that it was said to the people long ago, ‘Do not murder, and anyone who murders will be subject to judgment.’ 22 But I tell you that anyone who is angry with his brother will be subject to judgment. Again, anyone who says to his brother, ‘Raca,’ is answerable to the Sanhedrin. But anyone who says, ‘You fool!’ will be in danger of the fire of hell (Matt 5:21-22 NIV).
The righteousness of the kingdom demands more than a legalistic view of murder; it demands a righteous attitude toward one another, not just a sparing of life. A righteous attitude toward one another starts with getting rid of all anger and rage toward one another (Matt 5:22a; Eph 4:31; Col 3:8) so that no one forfeits their inheritance in the kingdom (Gal 5:20).
Just as sin has reigned in death, in the lives of sinners, so now, in the lives of those in the kingdom of heaven – grace might reign through righteousness to bring eternal life through Jesus Christ our Lord (Rom 5:21). May God bless us to teach and practice the righteousness of His kingdom (Matt 5:19b) – Amen.