"Blessed are the pure in heart for they shall see God."
Matthew 5:8

To be pure in heart is to be faithful to God; to be driven by right motives to right actions; to love and seek out justice, mercy, and compassion.

What are mortals, that they could be Pure, or those born of woman, that they could be righteous?  Job 15:14

We all sin, all mankind. We struggle against it from the moment we are born until the moment we die. Our hearts are stained with selfishness, greed, hatred, and lust. Purity of Heart is an unattainable goal for our fallen flesh.

But when the kindness and love of God our Savior appeared, he saved us, not because of righteous things we had done, but because of his mercy. He saved us through the washing of rebirth and renewal by the Holy Spirit, whom he poured out on us generously through Jesus Christ our Savior.  Titus 3:4-6

Purity in our heart does not mean sinless perfection, it means having a heart that has been cleansed by the sacrifice of Jesus for our sins. It means accepting His sacrifice and chasing after His holiness. It means accepting the fact that we can never be clean on our own. In order to have a pure heart, we must allow it to be cleansed and covered by the righteousness of Jesus Christ.

Who may ascend the mountain of the Lord? Who may stand in his holy place?  The one who has clean hands and a pure heart...  Psalm 24:3-4

 "Who may stand in his holy place?" Who may see God? The one whose heart is devoted to righteousness; the one whose hands work for good. Such a person will see God -- not only in Heaven, but here on the earth.

Religion that God our Father accepts as pure and faultless is this: to look after orphans and widows in their distress and to keep oneself from being polluted by the world.  James 1:27

If we have a heart that seeks after the things God cherishes (like mercy, love, and compassion) we will surely find Him in those very things. We will see Him in the earth, working through us. We will feel His presence and know the joy that it is to be bathed in His mercy and grace. Our hearts will seek out the hurting, lost, and desperate of this world, just as Jesus did. We will not allow ourselves to sit idly by while those around us suffer. A heart that is pure is not focused on itself, but on the love and power of God alive within it.

... let us draw near to God with a sincere heart and with the full assurance that faith brings, having our hearts sprinkled to cleanse us from a guilty conscience and having our bodies washed with pure water.  Hebrews 10:22

Above all, a pure heart does not live in condemnation. It knows is own tendencies, but it also knows the grace it has received. A heart that has been washed clean by the blood of Jesus knows that it is made clean, not by its own righteousness, but by His. It is not afraid to press closer into God, knowing that He sees, not what it once was, but the spotless vision of His Son reflected in the heart of His rescued child.