"Without pollution or defilement..."
Proverbs 20:30

see also: Reflections on Purity & Purification

Purification is a Personal Act of Obedience

And Moses, and Aaron, and all the congregation of the children of Israel, did to the Levites according unto all that the Lord commanded Moses concerning the Levites, so did the children of Israel unto them. And the Levites were purified, and they washed their clothes; and Aaron offered them as an offering before the Lord; and Aaron made an atonement for them to cleanse them. And after that went the Levites in to do their service in the tabernacle of the congregation before Aaron, and before his sons: as the Lord had commanded Moses concerning the Levites, so did they unto them.
(Numbers 8:20–22)

And a man that is clean shall gather up the ashes of the heifer, and lay them up without the camp in a clean place, and it shall be kept for the congregation of the children of Israel for a water of separation: it is a purification for sin.
(Numbers 19:9)

He that toucheth the dead body of any man shall be unclean seven days. He shall purify himself with it on the third day, and on the seventh day he shall be clean: but if he purify not himself the third day, then the seventh day he shall not be clean.
(Numbers 19:11–12)

And the clean person shall sprinkle upon the unclean on the third day, and on the seventh day: and on the seventh day he shall purify himself, and wash his clothes, and bathe himself in water, and shall be clean at even. But the man that shall be unclean, and shall not purify himself, that soul shall be cut off from among the congregation, because he hath defiled the sanctuary of the Lord: the water of separation hath not been sprinkled upon him; he is unclean.
(Numbers 19:19–20)

And do ye abide without the camp seven days: whosoever hath killed any person, and whosoever hath touched any slain, purify both yourselves and your captives on the third day, and on the seventh day. And purify all your raiment, and all that is made of skins, and all work of goats’ hair, and all things made of wood. And Eleazar the priest said unto the men of war which went to the battle, This is the ordinance of the law which the Lord commanded Moses; Only the gold, and the silver, the brass, the iron, the tin, and the lead, Every thing that may abide the fire, ye shall make it go through the fire, and it shall be clean: nevertheless it shall be purified with the water of separation: and all that abideth not the fire ye shall make go through the water.
(Numbers 31:19–23)

And the children of the captivity kept the passover upon the fourteenth day of the first month. For the priests and the Levites were purified together, all of them were pure, and killed the passover for all the children of the captivity, and for their brethren the priests, and for themselves. And the children of Israel, which were come again out of captivity, and all such as had separated themselves unto them from the filthiness of the heathen of the land, to seek the Lord God of Israel, did eat, And kept the feast of unleavened bread seven days with joy: for the Lord had made them joyful, and turned the heart of the king of Assyria unto them, to strengthen their hands in the work of the house of God, the God of Israel.
(Ezra 6:19–22)

And the priests and the Levites purified themselves, and purified the people, and the gates, and the wall.
(Nehemiah 12:30)

And both the singers and the porters kept the ward of their God, and the ward of the purification, according to the commandment of David, and of Solomon his son.
(Nehemiah 12:45)

Even a child is known by his doings, whether his work be pure, and whether it be right.
(Proverbs 20:11)

The way of man is froward and strange: but as for the pure, his work is right.
(Proverbs 21:8)

Them take, and purify thyself with them, and be at charges with them, that they may shave their heads: and all may know that those things, whereof they were informed concerning thee, are nothing; but that thou thyself also walkest orderly, and keepest the law. As touching the Gentiles which believe, we have written and concluded that they observe no such thing, save only that they keep themselves from things offered to idols, and from blood, and from strangled, and from fornication. Then Paul took the men, and the next day purifying himself with them entered into the temple, to signify the accomplishment of the days of purification, until that an offering should be offered for every one of them.
(Acts 21:24–26)

Seeing ye have purified your souls in obeying the truth through the Spirit unto unfeigned love of the brethren, see that ye love one another with a pure heart fervently.
(1 Peter 1:22)

The Act of Purification is by Faith

And when there had been much disputing, Peter rose up, and said unto them, Men and brethren, ye know how that a good while ago God made choice among us, that the Gentiles by my mouth should hear the word of the gospel, and believe. And God, which knoweth the hearts, bare them witness, giving them the Holy Ghost, even as he did unto us; And put no difference between us and them, purifying their hearts by faith. Now therefore why tempt ye God, to put a yoke upon the neck of the disciples, which neither our fathers nor we were able to bear? But we believe that through the grace of the Lord Jesus Christ we shall be saved, even as they.
(Acts 15:7–11)

Seeing ye have purified your souls in obeying the truth through the Spirit unto unfeigned love of the brethren, see that ye love one another with a pure heart fervently.
(1 Peter 1:22)

Purity is Demanded

Let no man despise thy youth; but be thou an example of the believers, in word, in conversation, in charity, in spirit, in faith, in purity.
(1 Timothy 4:12)

The elder women as mothers; the younger as sisters, with all purity.
(1 Timothy 5:2)

Draw nigh to God, and he will draw nigh to you. Cleanse your hands, ye sinners; and purify your hearts, ye double minded.
(James 4:8)

And every man that hath this hope in him purifieth himself, even as he is pure.
(1 John 3:3)

Seeing ye have purified your souls in obeying the truth through the Spirit unto unfeigned love of the brethren, see that ye love one another with a pure heart fervently.
(1 Peter 1:22)

Pure Heart Required Before God

Who shall ascend into the hill of the Lord? or who shall stand in his holy place? He that hath clean hands, and a pure heart; who hath not lifted up his soul unto vanity, nor sworn deceitfully. He shall receive the blessing from the Lord, and righteousness from the God of his salvation.
(Psalm 24:3–5)

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

Now the end of the commandment is charity out of a pure heart, and of a good conscience, and of faith unfeigned.
(1 Timothy 1:5)

Flee also youthful lusts: but follow righteousness, faith, charity, peace, with them that call on the Lord out of a pure heart.
(2 Timothy 2:22)

Purity Required to Serve

Likewise must the deacons be grave, not doubletongued, not given to much wine, not greedy of filthy lucre; Holding the mystery of the faith in a pure conscience. And let these also first be proved; then let them use the office of a deacon, being found blameless.
(1 Timothy 3:8–10)

Lay hands suddenly on no man, neither be partaker of other men's sins: keep thyself pure.
(1 Timothy 5:22)

We then, as workers together with him, beseech you also that ye receive not the grace of God in vain. (For he saith, I have heard thee in a time accepted, and in the day of salvation have I succoured thee: behold, now is the accepted time; behold, now is the day of salvation.) Giving no offence in any thing, that the ministry be not blamed: But in all things approving ourselves as the ministers of God, in much patience, in afflictions, in necessities, in distresses, In stripes, in imprisonments, in tumults, in labours, in watchings, in fastings; By pureness, by knowledge, by longsuffering, by kindness, by the Holy Ghost, by love unfeigned, By the word of truth, by the power of God, by the armour of righteousness on the right hand and on the left, By honour and dishonour, by evil report and good report: as deceivers, and yet true; As unknown, and yet well known; as dying, and, behold, we live; as chastened, and not killed; As sorrowful, yet alway rejoicing; as poor, yet making many rich; as having nothing, and yet possessing all things.
(2 Corinthians 6:1–10)

God as the Purifier

And he shall sit as a refiner and purifier of silver: and he shall purify the sons of Levi, and purge them as gold and silver, that they may offer unto the Lord an offering in righteousness.
(Malachi 3:3)

I will turn my hand upon thee, and purely purge away thy dross, and take away all thy tin.
(Isaiah 1:25)

Who being the brightness of his glory, and the express image of his person, and upholding all things by the word of his power, when he had by himself purged our sins, sat down on the right hand of the Majesty on high.
(Hebrews 1:3)

Purified by Christ’s Sacrifice

For if the blood of bulls and of goats, and the ashes of an heifer sprinkling the unclean, sanctifieth to the purifying of the flesh: How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God?
(Hebrews 9:13–14)

Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.
(Hebrews 10:22)

But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin.
(1 John 1:7)

Ongoing Sanctification

This is the will of God, even your sanctification, that ye should abstain from fornication: That every one of you should know how to possess his vessel in sanctification and honour.
(1 Thessalonians 4:3–4)

Being confident of this very thing, that he which hath begun a good work in you will perform it until the day of Jesus Christ.
(Philippians 1:6)

And every man that hath this hope in him purifieth himself, even as he is pure.
(1 John 3:3)

Impurity and the Conscience

Unto the pure all things are pure: but unto them that are defiled and unbelieving is nothing pure; but even their mind and conscience is defiled.
(Titus 1:15)

Because that, when they knew God, they glorified him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened... Wherefore God also gave them up to uncleanness through the lusts of their own hearts, to dishonour their own bodies between themselves.
(Romans 1:21, 24)

Who being past feeling have given themselves over unto lasciviousness, to work all uncleanness with greediness.
(Ephesians 4:19)