Tartar hides deep under our gums. Even after brushing it has to be dug out. When I know I have to go to the dentist I brush with extra diligence in the days approaching the appointment. And yet all this junk still comes out from under my gumline when the hygienist cleans with her instruments. Arrrgggghhhh! I thought I got that out.
I am learning that it is the same with confession and repentance. Sometimes I have to be really still for a long period and reflect to allow the Holy Spirit to scrape the recesses of my hearts. A cursory brushing won’t do.