In the next Beatitude ("Blessed are those who hunger and thirst for righteousness") Rory explains what Jesus meant by righteous living in Matthew 5:1-6. We see in these passages that our lives can only have meaning in God when we are made righteous in him.
Matthew 5:1 - 5:6
5:1 Seeing the crowds, he went up on the mountain, and when he sat down, his disciples came to him.
2 And he opened his mouth and taught them, saying:
3 “Blessed are the poor in spirit, for theirs is the kingdom of heaven.
4 “Blessed are those who mourn, for they shall be comforted.
5 “Blessed are the meek, for they shall inherit the earth.
6 “Blessed are those who hunger and thirst for righteousness, for they shall be satisfied.