The Beatitudes compare the world of man and the kingdom of God. Attitudes and characteristics that result from following Jesus Christ result in heavenly results.
The sixth Beatitude relates to the pure of heart. All sinners who are born again through faith in Jesus receive a pure heart. The notion of divine purity is expressed in Psalm 51, when King David asks God to “create in me a clean heart, O God, and renew a right spirit within me.”
Just like the other elements of the Beatitudes, the state of being — meek, poor in spirit, merciful, pure of heart — is not a natural state. The pure of heart are not free of sin through their own actions. Rather, the sinner receives a pure heart through the redemption that only Christ can give.
MATTHEW 5:8
8 Blessed are the pure in heart: for they shall see God.
