Psalm 51:10

Create in me a pure heart, O God, and renew a steadfast spirit within me.

Create in me a pure heart, O God 
Psalm 24:3-4  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, who does not trust in an idol or swear by a false god.
Psalm 78:36-37  But then they would flatter him with their mouths, lying to him with their tongues; their hearts were not loyal to him, they were not faithful to his covenant.
Matthew 5:8  "Blessed are the pure in heart, for they will see God."
Acts 15:7-9  After much discussion, Peter got up and addressed them: "Brothers, you know that some time ago God made a choice among you that the Gentiles might hear from my lips the message of the gospel and believe. God, who knows the heart, showed that he accepted them by giving the Holy Spirit to them, just as he did to us. He did not discriminate between us and them, for he purified their hearts by faith."

and renew a steadfast spirit within me 
Ezekiel 18:30-32  "Therefore, you Israelites, I will judge each of you according to your own ways, declares the Sovereign LORD. Repent! Turn away from all your offenses; then sin will not be your downfall. Rid yourselves of all the offenses you have committed, and get a new heart and a new spirit. Why will you die, people of Israel? For I take no pleasure in the death of anyone, declares the Sovereign LORD. Repent and live!"
Ezekiel 36:26-28  " 'I will give you a new heart and put a new spirit in you; I will remove from you your heart of stone and give you a heart of flesh. And I will put my Spirit in you and move you to follow my decrees and be careful to keep my laws. Then you will live in the land I gave your ancestors; you will be my people, and I will be your God.' "

Scriptures taken from the Holy Bible, New International Version® NIV®, Copyright© 1973, 1978, 1984, 2011 by Biblica, Inc.® Used by permission. All rights reserved worldwide. 
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