This is a story a friend of mine shared about an experience on her mission.
"I want to tell you a little about what I have been learning about the atonement. One of my former companions had a little bump on her forehead right above her eye when she was in elementary school. It hurt really bad and she complained and complained about it, so finally they took her to the doctor, twice. Both times they said she was fine and sent her home. A bit later, she got hit with a ball on her head. What looked like a zit (the sore she complained about) burst open and all of this puss and blood exploded out. She went to the doctor, and he cleaned the area and sent her home. Shortly afterward, that same spot hurt again, so badly that even her bangs touching the area caused her pain. Finally, they took her to a doctor who would open up the healed (former) wound. Again, infection spurted out. The doctor cleaned out the abscess and it went so deep that the infection went back to her skull. She would had to be packed and cleaned every day, so the wound could heal inside out. That was the problem. She had a deep infection right above her eye, but cleaning out the infection, partially, and then placing a band aid over the wound didn't heal her. It looked healed from the outside, but the infection came back even worse.This is like the atonement. We try to heal from the outside in, while the Savior heals from the inside out. The abscess didn't heal until it was able to heal from the inside out. Putting a band aid over our hurts or covering up our sins or avoiding our shortcomings doesn't heal us. We can only cover up our hurts for so long until we burst. We have to use the Atonement to heal from the inside out."