Be clean INSIDE and out!!!! The Lord sees the inward self!  One time I was teaching Primary kids. I used different makeup to illustrate what it would be like if people could see certain sins. I told them when someone smokes, maybe you can smell it, but what if they gossip? Can you see it? Then I took eyebrow pencil and scribbled on my mouth. What if they look at bad pictures or watch bad movies? I then took make up and made weird squiggly patterns from my eyes. I did thing about hearing, etc. Then my face looked awful. I then said some people might try to cover up their sins. I used cover up on the makeup, but of course it didn't do well. I said, People might lie to cover up sins, etc. THEN, I used cleanser and water and cleaned the sins away.  That was the atonement. There is only ONE way to get rid of the sins. And, we must try to stay clean inside and out. But, there is always the atonement.