To CLEANSE, purify, make clean — the root of 'catharsis'; used of ritual purification, of healing (Jesus 'cleanses' lepers, Mark 1:41), and of moral cleansing from sin. ⚠ At 1 John 1:7 'the blood of Jesus his Son CLEANSES us from all sin' — and the verb is PRESENT tense, a continual washing rather than a single past scrub, which is the theological hinge: it lands in the same breath as 'walk in the light', cutting against any idea that walking in the light means being already sinless. The one in the light is not the one who has no sin (1:8 forbids that) but the one whose sin is being continually cleansed. The word returns at 1:9, God faithful and just 'to forgive us our sins and to CLEANSE us from all unrighteousness' — the same cleansing, now tied to the confessing mouth. It carries the imagery of the sacrificial system, where blood purifies (Hebrews 9:22), into the moral life. → first discussed at 1 John 1:7