Our Lord Jesus Christ in his famous discourse uttered this Holy Spirit inspired words, "blessed are the pure in heart for they shall see God."
Only they who are pure in heart shall see God. If you are not pure in heart you will never see God.
The psalmist puts it another way by asking a question and then answering it. Psa 24:3-4 Who shall ascend the hill of the LORD? And who shall stand in his holy place?
He who has clean hands and a pure heart, who does not lift up his soul to what is false and does not swear deceitfully.
You may now be thinking like Solomon in the book of proverbs: Who can say, "I have made my heart pure; I am clean from sin"? Proverb 20:9
Can you really say you have made your heart pure; I am clean from sin? If you can then you will see God and can ascend up his hill and stand in his holy place.
You may be suspicious at this point if anyone answers possitively because Jesus once said that it is "What comes out of a person is what defiles him. For from within, out of the heart of man, come evil thoughts, sexual immorality, theft, murder, adultery, coveting, wickedness, deceit, sensuality, envy, slander, pride, foolishness. All these evil things come from within, and they defile a person." Mark 7:20-23
The Apostle Paul adds to this impurity, idolatry, socery, enmity, strife, fits of anger, rivalries, dissensions, drunkeness, orgies and things like these, that those who do such things will not inherit the kingdom of God.
If you are found innocent of any of the works mentioned above then you are pure in heart and can stand and ascend up the Holy hill of God.
Or perhaps you understand the condition of your heart to be more like Paul in Romans 7, 'Oh the wretched man that I am, who will deliver me from this body (heart) of death?'
Paul goes on to say in Rom 7:25 Thanks be to God through Jesus Christ our Lord!
How does Jesus Christ deliver you from your evil heart?
By his death on the cross and his ressurection. Becuase you believe in him by faith He has given you a new heart, to put it in old Christian language, 'you have been born again'. Listen to what Peter says about this: 1Peter 1:22-23 Having purified your souls by your obedience to the truth for a sincere brotherly love, love one another earnestly from a pure heart, since you have been born again, not of perishable seed but of imperishable, through the living and abiding word of God;
But you may say that I don't feel 'born again' or I'm still the same person.
That may be true and what you need to do is pray like David when he prayed in Psalm 51:10 'Create in me a clean heart, O God, and renew a right spirit within me'.
You will also need to throw away your former hope which made you think that you were 'converted' or 'born again' and believe afresh the gospel of Jesus Christ. God will come and cleanse your heart by faith (Acts 15:9).
You may say, I do feel born again but yet I know that there is sin in my heart, does that mean that I will never see God?
The good news is yes that you will see God because what makes you pure is Jesus Christ and his purity. To put it simply, you as a Christian have the entire righteousness of Jesus. Jesus never sinned so it is as if you never sinned; you are perfect in the sight of God when you come to Him because you are always wearing the Jacket (righteousness) of Jesus. This is called in theological terms Imputed righteousness. Personally I love this 'doctrine' so much that I called my blog counted rigteous in Christ.
You may then ask the question, does that then mean that we don't strive to be pure in heart?
Of course we do. Paul puts it this way in 2Co 7:1 Since we have these promises, beloved, let us cleanse ourselves from every defilement of body and spirit, bringing holiness to completion in the fear of God.
As a Christian you have the righteousness of Jesus Christ which means that you are pure, and because you are in Jesus Christ, God is transforming you day by day to become more like his Son, Jesus Christ.
Do you get it?
We are pure because of Jesus and what he has done - but we become pure in heart, that is, it has its effect in our lives as we conform ourselves to Jesus Christ. This is a process. But we can always come before God, ascend up his holy hill because of Jesus Christ and when we repent of our sins He will always forgive us.
You can read this text every day, 'Blessed are the pure in heart for they shall see God', and say - Jesus Christ is my perfect righteousness. He has made me pure, because he has made me pure and righteous I will live my life in conformity to Jesus's righteousness and not to the world. When I do fail and don't feel pure in heart, I will confess my sins, repent from them and say every time, Jesus is my righteousness. And immediately I can come to God, to pray and enjoy his presence and I don't have to wait, or go and do something because Jesus has already offered up the sacrifice of atonement.