Taharah is the Hebrew word for the state the body returns to after immersion. KJV, ESV, NASB, and NIV all translate the tahor/tamei binary as clean and unclean, and English readers hear clean as morally good and unclean as morally bad. That is wrong. The state has nothing to do with sin.

The high priest who has handled a holy sacrifice is tamei until he immerses. A bride after her menstrual cycle is tamei until she immerses. There is nothing morally wrong with either of them. Their bodies have moved through ritual states the way bodies do, and they need to return. Taharah is the state of being ready, not the state of being innocent.

Mikvah does not remove sin. Mikvah restores the body's covenant readiness. Taharah is the readiness, tum'ah is the drift, and the water is the way back.