'Purify' in the Bible

Now the passover of the Jews was at hand: and many went up to Jerusalem out of the country before the passover, to purify themselves.

these take, and purify thyself with them, and be at charges for them, that they may shave their heads: and all shall know that there is no truth in the things whereof they have been informed concerning thee; but that thou thyself also walkest orderly, keeping the law.

who gave himself for us, that he might redeem us from all iniquity, and purify unto himself a people for his own possession, zealous of good works.

Draw nigh to God, and he will draw nigh to you. Cleanse your hands, ye sinners; and purify your hearts, ye doubleminded.