Purity of heart is a work in progress in which both God and man share responsibility. Many scriptures show that God will cleanse by pardoning sin. But our responsibility in cleansing is very important and frequently mentioned along with what we must do to be cleansed. Notice how clearly James shows purifying is our responsibility: "Draw near to God and He will draw near to you. Cleanse your hands, you sinners; and purify your hearts, you double-minded" (James 4:8).
How is this purifying done? I Peter 1:22 makes a summary statement: "Since you have purified your souls in obeying the truth through the Spirit in sincere love of the brethren, love one another fervently with a pure heart." Obedience to the truth through the Spirit purifies our character by inculcating right habits within it.
After commanding us to clean ourselves up, Isaiah adds, "Put away the evil of your doings from before My eyes. Cease to do evil, learn to do good; seek justice, rebuke the oppressor; defend the fatherless, plead for the widow" (Isaiah 1:16-17). Likewise, after admonishing us to guard our heart, our Father says:
Put away from you a deceitful mouth, and put perverse lips far from you. Let your eyes look straight ahead, and your eyelids look right before you. Ponder the path of your feet, and let all your ways be established. Do not turn to the right or the left; remove your foot from evil. (Proverbs 4:24-27)
Jeremiah 4:14 adds, "O Jerusalem, wash your heart from wickedness, that you may be saved. How long shall your evil thoughts lodge within you?"
Psalm 24:3-4 asks a searching question and gives a clear and important answer to all of us: "Who may ascend into the hill of the LORD? Or who may stand in His holy place? He who has clean hands and a pure heart, who has not lifted up his soul to an idol, nor sworn deceitfully." These two brief verses broadly cover conduct, motivation, attitude, and prioritizing one's life.
To meet these qualifications requires "truth in the inward parts" (Psalm 51:6). A deceitful heart will never meet the standards because it does not operate from a foundation of godly integrity. David says in verse 5 that, humanly, he was shaped in iniquity. God, with our cooperation through faith, is ultimately the Creator of a pure heart in us, but it is a protracted process achieved by imparting a holy nature by His Spirit. This unites us with a holy Christ, with whom we fellowship, washing us in the blood of the Lamb so that with His aid we can mortify the flesh and live toward God, giving Him first priority in everything.
We will never be pure as God is pure in this life. Our purity is at best only in part. We are partly purified from our former darkness; our will is partly purified from its rebellion; our desires are partly purified from desires, avarice and pride. But the work of cleansing has begun, and God is faithful to finish what He starts (Philippians 1:6).
Interestingly, when Peter refers to God's calling of Gentiles in Acts 15:9, he says God "made no distinction between us and them, purifying their hearts by faith." He uses "purifying" in the sense of a continuous experience. In Titus 3:5, Paul also uses "renewing of the Holy Spirit" in the same ongoing sense. We must see purity of heart in this sense because as James 3:2, 8 states, "For we all stumble in many things. If anyone does not stumble in word, he is a perfect man, able also to bridle the whole body. . . . But no man can tame the tongue. It is an unruly evil, full of deadly poison." By daily denying the self, sincerely confessing and wholehearted obedience, we work toward purity.
However, it is not enough to be pure in words and outward conduct. Purity of desires, motives, and intents should characterize the child of God. We need to examine ourselves, searching diligently whether we have freed ourselves from the dominion of hypocrisy. Are our affections set on things above? Has the fear of the Lord grown strong enough that we love what He loves and hate what He hates? Are we conscious of and do we deeply grieve over the filth we yet find within ourselves? Are we conscious of our foul thoughts, vile imaginations, evil desires? Do we mourn over our pride? Perhaps the heaviest burden of a pure heart is seeing the ocean of unclean things still in him, casting its filth into his life and fouling what he does.