All born-again Christians are pure in heart. It's the same reason why all water is wet. It's the very nature of it.
Thank God that the gospel of the grace of Christ has given us believers a new heart which is pure because it is in Christ!
I believe that scripture teaches that we have new hearts now in Christ as a new creation in Him.
In the Old Testament David cried out prophetically - looking into this New Covenant and sais - "Create in me a clean heart O God". Jesus Himself says to "clean up the inside of the cup and the vessel will be clean".
We don't need to search our hearts for wrong things - we need to have our minds renewed to the truth of Christ living in us now.
It's the flesh that "speaks" to us as all the "works" in Gal 5 are from the flesh. We are not "in the flesh" as Paul says in Romans 8:9 - but we are "in the Spirit" - our inner man in Christ.
We need as Christians to learn to live from this new heart that was "created" in us because of Christ's finished work for us.
I firmly believe we are confusing the "desires of the flesh which still has the law of sin in it" ( Romans 7:23 ) and wrongly calling it our heart.
We have been circumcised with the circumcision of the heart - called the circumcision of Christ and the body of flesh. Col 2:11. This is also called "being sealed by the Holy Spirit" Eph 1:13
The Holy Spirit "cut away" ( as in physical circumcision ) the body of the flesh from the inner man who is in Christ - the new creation - created in righteousness and holiness. Eph 4:23
Here are the reasons why I believe we Christians have a new heart now in Christ and not a corrupted heart. We need to learn how to live from this new heart which is where Christ is in us as one spirit by the Holy Spirit.
The believers new heart in Christ is created in righteousness and holiness: First it was prophesied in the Old Testament.
Ezekiel 36:26 (NASB)
[SUP]26 [/SUP] "Moreover, I will give you a new heart and put a new spirit within you; and I will remove the heart of stone ( old man ) from your flesh and give you a heart of flesh. ( new man in Christ )
Romans 2:29 (NASB)
[SUP]29 [/SUP] But he is a Jew who is one inwardly; and circumcision is that which is of the heart, by the Spirit, not by the letter; and his praise is not from men, but from God.
By grace we have been given a new heart that is obedient.
Romans 6:17 (NASB)
[SUP]17 [/SUP] But thanks be to God that though you were slaves of sin, you became obedient from the heart to that form of teaching to which you were committed,
God cleaned house and moved in. God will not dwell in unrighteousness. God through the Holy Spirit is in our inner man now.
Ephesians 3:16-17 (NASB)
[SUP]16 [/SUP] that He would grant you, according to the riches of His glory, to be strengthened with power through His Spirit in the inner man,
[SUP]17 [/SUP] so that Christ may dwell in your hearts through faith; and that you, being rooted and grounded in love,
God sealed us and gave us the Holy Spirit in our new hearts.
2 Corinthians 1:22 (NASB)
[SUP]22 [/SUP] who also sealed us and gave us the Spirit in our hearts as a pledge.
We have the Spirit of God's Son in our hearts now.
Galatians 4:6 (NASB)
[SUP]6 [/SUP] Because you are sons, God has sent forth the Spirit of His Son into our hearts, crying, "Abba! Father!"
God has cleansed our hearts by faith.
Acts 15:8-9 (NASB)
[SUP]8 [/SUP] "And God, who knows the heart, testified to them giving them the Holy Spirit, just as He also did to us;
[SUP]9 [/SUP] and He made no distinction between us and them, cleansing their hearts by faith.
We love from our hearts now as it is pure.
1 Timothy 1:5 (NASB)
[SUP]5 [/SUP] But the goal of our instruction is love from a pure heart and a good conscience and a sincere faith.
2 Timothy 2:22 (NASB)
[SUP]22 [/SUP] Now flee from youthful lusts and pursue righteousness, faith, love and peace, with those who call on the Lord from a pure heart. (this is a believer in Christ..hang around them )
1 Peter 3:4 (NASB)
[SUP]4 [/SUP] but let it be the hidden person of the heart, with the imperishable quality of a gentle and quiet spirit, which is precious in the sight of God.
There are more but this should work to show that the believer has a new heart in Christ.
We still have the flesh to deal with in our bodies and we are admonished to not to yield to that...but all that is a different subject.